cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A334267 Numbers k such that the k-th composition in standard order is both a Lyndon word and a reversed co-Lyndon word.

Original entry on oeis.org

0, 1, 2, 4, 6, 8, 12, 14, 16, 20, 24, 26, 28, 30, 32, 40, 48, 52, 56, 58, 60, 62, 64, 72, 80, 84, 96, 100, 104, 106, 108, 112, 116, 118, 120, 122, 124, 126, 128, 144, 160, 164, 168, 192, 200, 208, 212, 216, 218, 224, 228, 232, 234, 236, 240, 244, 246, 248, 250
Offset: 1

Views

Author

Gus Wiseman, Apr 22 2020

Keywords

Comments

Also numbers whose binary expansion is both a reversed Lyndon word and a co-Lyndon word.
A Lyndon word is a finite sequence of positive integers that is lexicographically strictly less than all of its cyclic rotations. Co-Lyndon is defined similarly, except with strictly greater instead of strictly less.
The k-th composition in standard order (graded reverse-lexicographic, A066099) is obtained by taking the set of positions of 1's in the reversed binary expansion of k, prepending 0, taking first differences, and reversing again. This gives a bijective correspondence between nonnegative integers and integer compositions.

Examples

			The sequence of all reversed co-Lyndon Lyndon words begins:
    0: ()            56: (1,1,4)        124: (1,1,1,1,3)
    1: (1)           58: (1,1,2,2)      126: (1,1,1,1,1,2)
    2: (2)           60: (1,1,1,3)      128: (8)
    4: (3)           62: (1,1,1,1,2)    144: (3,5)
    6: (1,2)         64: (7)            160: (2,6)
    8: (4)           72: (3,4)          164: (2,3,3)
   12: (1,3)         80: (2,5)          168: (2,2,4)
   14: (1,1,2)       84: (2,2,3)        192: (1,7)
   16: (5)           96: (1,6)          200: (1,3,4)
   20: (2,3)        100: (1,3,3)        208: (1,2,5)
   24: (1,4)        104: (1,2,4)        212: (1,2,2,3)
   26: (1,2,2)      106: (1,2,2,2)      216: (1,2,1,4)
   28: (1,1,3)      108: (1,2,1,3)      218: (1,2,1,2,2)
   30: (1,1,1,2)    112: (1,1,5)        224: (1,1,6)
   32: (6)          116: (1,1,2,3)      228: (1,1,3,3)
   40: (2,4)        118: (1,1,2,1,2)    232: (1,1,2,4)
   48: (1,5)        120: (1,1,1,4)      234: (1,1,2,2,2)
   52: (1,2,3)      122: (1,1,1,2,2)    236: (1,1,2,1,3)
The sequence of terms together with their binary expansions and binary indices begins:
    0:      0 ~ {}            56:  111000 ~ {4,5,6}
    1:      1 ~ {1}           58:  111010 ~ {2,4,5,6}
    2:     10 ~ {2}           60:  111100 ~ {3,4,5,6}
    4:    100 ~ {3}           62:  111110 ~ {2,3,4,5,6}
    6:    110 ~ {2,3}         64: 1000000 ~ {7}
    8:   1000 ~ {4}           72: 1001000 ~ {4,7}
   12:   1100 ~ {3,4}         80: 1010000 ~ {5,7}
   14:   1110 ~ {2,3,4}       84: 1010100 ~ {3,5,7}
   16:  10000 ~ {5}           96: 1100000 ~ {6,7}
   20:  10100 ~ {3,5}        100: 1100100 ~ {3,6,7}
   24:  11000 ~ {4,5}        104: 1101000 ~ {4,6,7}
   26:  11010 ~ {2,4,5}      106: 1101010 ~ {2,4,6,7}
   28:  11100 ~ {3,4,5}      108: 1101100 ~ {3,4,6,7}
   30:  11110 ~ {2,3,4,5}    112: 1110000 ~ {5,6,7}
   32: 100000 ~ {6}          116: 1110100 ~ {3,5,6,7}
   40: 101000 ~ {4,6}        118: 1110110 ~ {2,3,5,6,7}
   48: 110000 ~ {5,6}        120: 1111000 ~ {4,5,6,7}
   52: 110100 ~ {3,5,6}      122: 1111010 ~ {2,4,5,6,7}
		

Crossrefs

Compositions of this type are counted by A334269.
Normal sequences of this type are counted by A334270.
Necklaces of this type are counted by A334271.
Necklaces of this type are ranked by A334274.
Binary (or reversed binary) Lyndon words are counted by A001037.
Lyndon compositions are counted by A059966.
Lyndon words whose reverse is not co-Lyndon are counted by A329324
Reversed Lyndon co-Lyndon compositions are ranked by A334266.
All of the following pertain to compositions in standard order (A066099):
- Length is A000120.
- Necklaces are A065609.
- Sum is A070939.
- Reverse is A228351 (triangle).
- Strict compositions are A233564.
- Constant compositions are A272919.
- Lyndon words are A275692.
- Reversed Lyndon words are A334265.
- Co-Lyndon words are A326774.
- Reversed co-Lyndon words are A328596.
- Length of Lyndon factorization is A329312.
- Length of Lyndon factorization of reverse is A334297.
- Length of co-Lyndon factorization is A334029.
- Length of co-Lyndon factorization of reverse is A329313.
- Distinct rotations are counted by A333632.
- Lyndon factorizations are counted by A333940.
- Co-Lyndon factorizations are counted by A333765.

Programs

  • Mathematica
    stc[n_]:=Differences[Prepend[Join@@Position[Reverse[IntegerDigits[n,2]],1],0]]//Reverse;
    lynQ[q_]:=Length[q]==0||Array[Union[{q,RotateRight[q,#1]}]=={q,RotateRight[q,#1]}&,Length[q]-1,1,And];
    colynQ[q_]:=Length[q]==0||Array[Union[{RotateRight[q,#],q}]=={RotateRight[q,#],q}&,Length[q]-1,1,And];
    Select[Range[0,100],colynQ[Reverse[stc[#]]]&&lynQ[stc[#]]&]

Formula

Intersection of A275692 and A328596.

A334270 Number of sequences of length n that cover an initial interval of positive integers and are both a reversed Lyndon word and a co-Lyndon word.

Original entry on oeis.org

1, 1, 1, 3, 10, 42, 224, 1505, 12380, 120439
Offset: 0

Views

Author

Gus Wiseman, Apr 24 2020

Keywords

Comments

Also the number of sequences of length n that cover an initial interval of positive integers and are both a Lyndon word and a reversed co-Lyndon word.
A Lyndon word is a finite sequence of positive integers that is lexicographically strictly less than all of its cyclic rotations. Co-Lyndon is defined similarly, except with strictly greater instead of strictly less.

Examples

			The a(1) = 1 through a(4) = 10 normal sequences:
  (1)  (2,1)  (2,1,1)  (2,1,1,1)
              (2,2,1)  (2,2,1,1)
              (3,2,1)  (2,2,2,1)
                       (3,1,2,1)
                       (3,2,1,1)
                       (3,2,2,1)
                       (3,2,3,1)
                       (3,3,2,1)
                       (4,2,3,1)
                       (4,3,2,1)
		

Crossrefs

These compositions are ranked by A334266 (standard) and A334267 (binary).
Compositions of this type are counted by A334269.
Necklace compositions of this type are counted by A334271.
Dominated by A334272 (the necklace version).
Normal sequences are counted by A000670.
Binary (or reversed binary) Lyndon words are counted by A001037.
Lyndon compositions are counted by A059966.
Normal Lyndon words are counted by A060223.
Normal sequences by length and Lyndon factorization length are A296372.
All of the following pertain to compositions in standard order (A066099):
- Lyndon words are A275692.
- Co-Lyndon words are A326774.
- Reversed Lyndon words are A334265.
- Reversed co-Lyndon words are A328596.
- Length of Lyndon factorization is A329312.
- Length of co-Lyndon factorization is A334029.
- Length of Lyndon factorization of reverse is A334297.
- Length of co-Lyndon factorization of reverse is A329313.

Programs

  • Mathematica
    lynQ[q_]:=Length[q]==0||Array[Union[{q,RotateRight[q,#1]}]=={q,RotateRight[q,#1]}&,Length[q]-1,1,And];
    colynQ[q_]:=Length[q]==0||Array[Union[{RotateRight[q,#],q}]=={RotateRight[q,#],q}&,Length[q]-1,1,And];
    allnorm[n_]:=If[n<=0,{{}},Function[s,Array[Count[s,y_/;y<=#]+1&,n]]/@Subsets[Range[n-1]+1]];
    Table[Length[Select[Join@@Permutations/@allnorm[n],lynQ[Reverse[#]]&&colynQ[#]&]],{n,0,6}]

A334297 Length of the Lyndon factorization of the reversed n-th composition in standard order.

Original entry on oeis.org

0, 1, 1, 2, 1, 1, 2, 3, 1, 1, 2, 1, 2, 2, 3, 4, 1, 1, 1, 1, 2, 1, 2, 1, 2, 2, 3, 2, 3, 3, 4, 5, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 3, 1, 2, 2, 2, 1, 2, 2, 2, 2, 3, 2, 3, 2, 3, 3, 4, 3, 4, 4, 5, 6, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 3, 1, 2
Offset: 0

Views

Author

Gus Wiseman, Apr 25 2020

Keywords

Comments

We define the Lyndon product of two or more finite sequences to be the lexicographically maximal sequence obtainable by shuffling the sequences together. For example, the Lyndon product of (231) with (213) is (232131), the product of (221) with (213) is (222131), and the product of (122) with (2121) is (2122121). A Lyndon word is a finite sequence that is prime with respect to the Lyndon product. Every finite sequence has a unique (orderless) factorization into Lyndon words, and if these factors are arranged in lexicographically decreasing order, their concatenation is equal to their Lyndon product. For example, (1001) has sorted Lyndon factorization (001)(1).
The k-th composition in standard order (graded reverse-lexicographic, A066099) is obtained by taking the set of positions of 1's in the reversed binary expansion of k, prepending 0, taking first differences, and reversing again. This gives a bijective correspondence between nonnegative integers and integer compositions.

Examples

			The 12345th composition is (1,7,1,1,3,1), with reverse (1,3,1,1,7,1), with Lyndon factorization ((1),(1,3),(1,1,7)), so a(12345) = 3.
		

Crossrefs

The non-reversed version is A329312.
The version for binary indices is A329313 (also the "co-" version).
Positions of 1's are A334265 (reversed Lyndon words).
Binary Lyndon words are counted by A001037 and ranked by A102659.
Lyndon compositions are counted by A059966 and ranked by A275692.
Normal Lyndon sequences are counted by A060223 (row sums of A296372).
All of the following pertain to compositions in standard order (A066099):
- Length is A000120.
- Necklaces are A065609.
- Sum is A070939.
- Reverse is A228351 (triangle).
- Strict compositions are A233564.
- Constant compositions are A272919.
- Lyndon words are A275692.
- Co-Lyndon words are A326774.
- Reversed co-Lyndon words are A328596.
- Aperiodic compositions are A328594.
- Distinct rotations are counted by A333632.
- Lyndon factorizations are counted by A333940.
- Length of co-Lyndon factorization is A334029.

Programs

  • Mathematica
    stc[n_]:=Differences[Prepend[Join@@Position[Reverse[IntegerDigits[n,2]],1],0]]//Reverse;
    lynQ[q_]:=Length[q]==0||Array[Union[{q,RotateRight[q,#]}]=={q,RotateRight[q,#]}&,Length[q]-1,1,And];
    lynfac[q_]:=If[Length[q]==0,{},Function[i,Prepend[lynfac[Drop[q,i]],Take[q,i]]][Last[Select[Range[Length[q]],lynQ[Take[q,#]]&]]]];
    Table[Length[lynfac[Reverse[stc[n]]]],{n,0,100}]

A329396 Numbers k such that the co-Lyndon factorization of the binary expansion of k is uniform.

Original entry on oeis.org

1, 2, 3, 4, 6, 7, 8, 10, 12, 14, 15, 16, 20, 24, 26, 28, 30, 31, 32, 36, 38, 40, 42, 48, 50, 52, 54, 56, 58, 60, 62, 63, 64, 72, 80, 84, 96, 98, 100, 104, 106, 108, 112, 114, 116, 118, 120, 122, 124, 126, 127, 128, 136, 140, 142, 144, 160, 164, 168, 170, 192
Offset: 1

Views

Author

Gus Wiseman, Nov 13 2019

Keywords

Comments

The co-Lyndon product of two or more finite sequences is defined to be the lexicographically minimal sequence obtainable by shuffling the sequences together. For example, the co-Lyndon product of (231) and (213) is (212313), the product of (221) and (213) is (212213), and the product of (122) and (2121) is (1212122). A co-Lyndon word is a finite sequence that is prime with respect to the co-Lyndon product. Equivalently, a co-Lyndon word is a finite sequence that is lexicographically strictly greater than all of its cyclic rotations. Every finite sequence has a unique (orderless) factorization into co-Lyndon words, and if these factors are arranged in a certain order, their concatenation is equal to their co-Lyndon product. For example, (1001) has sorted co-Lyndon factorization (1)(100).
A sequence of words is uniform if they all have the same length.

Examples

			The sequence of terms together with their co-Lyndon factorizations begins:
   1:      (1) = (1)
   2:     (10) = (10)
   3:     (11) = (1)(1)
   4:    (100) = (100)
   6:    (110) = (110)
   7:    (111) = (1)(1)(1)
   8:   (1000) = (1000)
  10:   (1010) = (10)(10)
  12:   (1100) = (1100)
  14:   (1110) = (1110)
  15:   (1111) = (1)(1)(1)(1)
  16:  (10000) = (10000)
  20:  (10100) = (10100)
  24:  (11000) = (11000)
  26:  (11010) = (11010)
  28:  (11100) = (11100)
  30:  (11110) = (11110)
  31:  (11111) = (1)(1)(1)(1)(1)
  32: (100000) = (100000)
  36: (100100) = (100)(100)
  38: (100110) = (100)(110)
  40: (101000) = (101000)
  42: (101010) = (10)(10)(10)
		

Crossrefs

Numbers whose binary expansion has uniform Lyndon factorization are A023758.
Numbers whose reversed binary expansion is Lyndon are A328596.
Numbers whose binary expansion is co-Lyndon are A275692.
Numbers whose trimmed binary expansion has Lyndon and co-Lyndon factorizations of equal lengths are A329395.

Programs

  • Mathematica
    colynQ[q_]:=Array[Union[{RotateRight[q,#],q}]=={RotateRight[q,#],q}&,Length[q]-1,1,And];
    colynfac[q_]:=If[Length[q]==0,{},Function[i,Prepend[colynfac[Drop[q,i]],Take[q,i]]]@Last[Select[Range[Length[q]],colynQ[Take[q,#]]&]]];
    Select[Range[100],SameQ@@Length/@colynfac[IntegerDigits[#,2]]&]

A329399 Numbers whose reversed binary expansion has uniform Lyndon factorization.

Original entry on oeis.org

1, 2, 3, 4, 6, 7, 8, 10, 12, 14, 15, 16, 20, 24, 26, 28, 30, 31, 32, 36, 38, 40, 42, 44, 48, 52, 54, 56, 58, 60, 62, 63, 64, 72, 80, 84, 88, 92, 96, 100, 104, 106, 108, 112, 116, 118, 120, 122, 124, 126, 127, 128, 136, 140, 142, 144, 152, 160, 164, 168, 170
Offset: 1

Views

Author

Gus Wiseman, Nov 13 2019

Keywords

Comments

We define the Lyndon product of two or more finite sequences to be the lexicographically maximal sequence obtainable by shuffling the sequences together. For example, the Lyndon product of (231) with (213) is (232131), the product of (221) with (213) is (222131), and the product of (122) with (2121) is (2122121). A Lyndon word is a finite sequence that is prime with respect to the Lyndon product. Equivalently, a Lyndon word is a finite sequence that is lexicographically strictly less than all of its cyclic rotations. Every finite sequence has a unique (orderless) factorization into Lyndon words, and if these factors are arranged in lexicographically decreasing order, their concatenation is equal to their Lyndon product. For example, (1001) has sorted Lyndon factorization (001)(1).
A sequence of words is uniform if they all have the same length.

Examples

			The sequence of terms together with their reversed binary expansions and Lyndon factorizations begins:
   1:      (1) = (1)
   2:     (01) = (01)
   3:     (11) = (1)(1)
   4:    (001) = (001)
   6:    (011) = (011)
   7:    (111) = (1)(1)(1)
   8:   (0001) = (0001)
  10:   (0101) = (01)(01)
  12:   (0011) = (0011)
  14:   (0111) = (0111)
  15:   (1111) = (1)(1)(1)(1)
  16:  (00001) = (00001)
  20:  (00101) = (00101)
  24:  (00011) = (00011)
  26:  (01011) = (01011)
  28:  (00111) = (00111)
  30:  (01111) = (01111)
  31:  (11111) = (1)(1)(1)(1)(1)
  32: (000001) = (000001)
  36: (001001) = (001)(001)
  38: (011001) = (011)(001)
  40: (000101) = (000101)
  42: (010101) = (01)(01)(01)
  44: (001101) = (001101)
  48: (000011) = (000011)
		

Crossrefs

Numbers whose binary expansion has uniform Lyndon factorization and uniform co-Lyndon factorization are A023758.
Numbers whose reversed binary expansion is Lyndon are A328596.
Numbers whose binary expansion is co-Lyndon are A275692.
Numbers whose trimmed binary expansion has Lyndon and co-Lyndon factorizations of equal lengths are A329395.

Programs

  • Mathematica
    lynQ[q_]:=Array[Union[{q,RotateRight[q,#]}]=={q,RotateRight[q,#]}&,Length[q]-1,1,And];
    lynfac[q_]:=If[Length[q]==0,{},Function[i,Prepend[lynfac[Drop[q,i]],Take[q,i]]][Last[Select[Range[Length[q]],lynQ[Take[q,#]]&]]]];
    Select[Range[100],SameQ@@Length/@lynfac[Reverse[IntegerDigits[#,2]]]&]

A329400 Length of the co-Lyndon factorization of the binary expansion of n with the most significant (first) digit removed.

Original entry on oeis.org

0, 1, 1, 2, 2, 1, 2, 3, 3, 2, 3, 1, 2, 1, 3, 4, 4, 3, 4, 2, 3, 2, 4, 1, 2, 2, 3, 1, 2, 1, 4, 5, 5, 4, 5, 3, 4, 3, 5, 2, 3, 3, 4, 2, 3, 2, 5, 1, 2, 2, 3, 1, 3, 2, 4, 1, 2, 1, 3, 1, 2, 1, 5, 6, 6, 5, 6, 4, 5, 4, 6, 3, 4, 4, 5, 3, 4, 3, 6, 2, 3, 3, 4, 2, 4, 3, 5
Offset: 1

Views

Author

Gus Wiseman, Nov 16 2019

Keywords

Comments

The co-Lyndon product of two or more finite sequences is defined to be the lexicographically minimal sequence obtainable by shuffling the sequences together. For example, the co-Lyndon product of (231) and (213) is (212313), the product of (221) and (213) is (212213), and the product of (122) and (2121) is (1212122). A co-Lyndon word is a finite sequence that is prime with respect to the co-Lyndon product. Equivalently, a co-Lyndon word is a finite sequence that is lexicographically strictly greater than all of its cyclic rotations. Every finite sequence has a unique (orderless) factorization into co-Lyndon words, and if these factors are arranged in a certain order, their concatenation is equal to their co-Lyndon product. For example, (1001) has sorted co-Lyndon factorization (1)(100).

Examples

			Decapitated binary expansions of 1..20 together with their co-Lyndon factorizations:
   1:     () =
   2:    (0) = (0)
   3:    (1) = (1)
   4:   (00) = (0)(0)
   5:   (01) = (0)(1)
   6:   (10) = (10)
   7:   (11) = (1)(1)
   8:  (000) = (0)(0)(0)
   9:  (001) = (0)(0)(1)
  10:  (010) = (0)(10)
  11:  (011) = (0)(1)(1)
  12:  (100) = (100)
  13:  (101) = (10)(1)
  14:  (110) = (110)
  15:  (111) = (1)(1)(1)
  16: (0000) = (0)(0)(0)(0)
  17: (0001) = (0)(0)(0)(1)
  18: (0010) = (0)(0)(10)
  19: (0011) = (0)(0)(1)(1)
  20: (0100) = (0)(100)
		

Crossrefs

The non-"co" version is A211097.
The version involving all digits is A329312.
Lyndon and co-Lyndon compositions are (both) counted by A059966.
Numbers whose reversed binary expansion is Lyndon are A328596.
Numbers whose binary expansion is co-Lyndon are A275692.
Numbers whose decapitated binary expansion is co-Lyndon are A329401.

Programs

  • Mathematica
    colynQ[q_]:=Array[Union[{RotateRight[q,#],q}]=={RotateRight[q,#],q}&,Length[q]-1,1,And];
    colynfac[q_]:=If[Length[q]==0,{},Function[i,Prepend[colynfac[Drop[q,i]],Take[q,i]]]@Last[Select[Range[Length[q]],colynQ[Take[q,#]]&]]];
    Table[If[n==0,0,Length[colynfac[Rest[IntegerDigits[n,2]]]]],{n,30}]

A329401 Numbers whose binary expansion without the most significant (first) digit is a co-Lyndon word.

Original entry on oeis.org

2, 3, 6, 12, 14, 24, 28, 30, 48, 52, 56, 58, 60, 62, 96, 104, 112, 114, 116, 120, 122, 124, 126, 192, 200, 208, 212, 224, 226, 228, 232, 234, 236, 240, 242, 244, 246, 248, 250, 252, 254, 384, 400, 416, 420, 424, 448, 450, 452, 456, 458, 464, 466, 468, 472, 474
Offset: 1

Views

Author

Gus Wiseman, Nov 16 2019

Keywords

Comments

A co-Lyndon word is a finite sequence that is lexicographically strictly greater than all of its cyclic rotations.

Examples

			The sequence of terms together with their binary expansions begins:
    2: (1,0)
    3: (1,1)
    6: (1,1,0)
   12: (1,1,0,0)
   14: (1,1,1,0)
   24: (1,1,0,0,0)
   28: (1,1,1,0,0)
   30: (1,1,1,1,0)
   48: (1,1,0,0,0,0)
   52: (1,1,0,1,0,0)
   56: (1,1,1,0,0,0)
   58: (1,1,1,0,1,0)
   60: (1,1,1,1,0,0)
   62: (1,1,1,1,1,0)
   96: (1,1,0,0,0,0,0)
  104: (1,1,0,1,0,0,0)
  112: (1,1,1,0,0,0,0)
  114: (1,1,1,0,0,1,0)
  116: (1,1,1,0,1,0,0)
  120: (1,1,1,1,0,0,0)
		

Crossrefs

The version involving all digits is A275692.
Binary Lyndon/co-Lyndon words are A001037.
A ranking of binary co-Lyndon words is A329318

Programs

  • Mathematica
    colynQ[q_]:=Array[Union[{RotateRight[q,#],q}]=={RotateRight[q,#],q}&,Length[q]-1,1,And];
    Select[Range[2,100],colynQ[Rest[IntegerDigits[#,2]]]&]

A333942 Number of multiset partitions of a multiset whose multiplicities are the parts of the n-th composition in standard order.

Original entry on oeis.org

1, 1, 2, 2, 3, 4, 4, 5, 5, 7, 9, 11, 7, 11, 11, 15, 7, 12, 16, 21, 16, 26, 26, 36, 12, 21, 26, 36, 21, 36, 36, 52, 11, 19, 29, 38, 31, 52, 52, 74, 29, 52, 66, 92, 52, 92, 92, 135, 19, 38, 52, 74, 52, 92, 92, 135, 38, 74, 92, 135, 74, 135, 135, 203, 15, 30, 47
Offset: 0

Views

Author

Gus Wiseman, Apr 16 2020

Keywords

Comments

A composition of n is a finite sequence of positive integers summing to n. The k-th composition in standard order (row k of A066099) is obtained by taking the set of positions of 1's in the reversed binary expansion of k, prepending 0, taking first differences, and reversing again. This gives a bijective correspondence between nonnegative integers and integer compositions.

Examples

			The a(1) = 1 through a(11) = 11 multiset partitions:
  {1}  {11}    {12}    {111}      {112}      {122}      {123}
       {1}{1}  {1}{2}  {1}{11}    {1}{12}    {1}{22}    {1}{23}
                       {1}{1}{1}  {2}{11}    {2}{12}    {2}{13}
                                  {1}{1}{2}  {1}{2}{2}  {3}{12}
                                                        {1}{2}{3}
  {1111}        {1112}        {1122}        {1123}
  {1}{111}      {1}{112}      {1}{122}      {1}{123}
  {11}{11}      {11}{12}      {11}{22}      {11}{23}
  {1}{1}{11}    {2}{111}      {12}{12}      {12}{13}
  {1}{1}{1}{1}  {1}{1}{12}    {2}{112}      {2}{113}
                {1}{2}{11}    {1}{1}{22}    {3}{112}
                {1}{1}{1}{2}  {1}{2}{12}    {1}{1}{23}
                              {2}{2}{11}    {1}{2}{13}
                              {1}{1}{2}{2}  {1}{3}{12}
                                            {2}{3}{11}
                                            {1}{1}{2}{3}
		

Crossrefs

The described multiset has A000120 distinct parts.
The sum of the described multiset is A029931.
Multisets of compositions are A034691.
The described multiset is a row of A095684.
Combinatory separations of normal multisets are A269134.
The product of the described multiset is A284001.
The version for prime indices is A318284.
The version counting combinatory separations is A334030.
All of the following pertain to compositions in standard order (A066099):
- Length is A000120.
- Sum is A070939.
- Strict compositions are A233564.
- Constant compositions are A272919.
- Length of Lyndon factorization is A329312.
- Dealings are counted by A333939.
- Distinct parts are counted by A334028.
- Length of co-Lyndon factorization is A334029.

Programs

  • Mathematica
    stc[n_]:=Differences[Prepend[Join@@Position[Reverse[IntegerDigits[n,2]],1],0]]//Reverse;
    ptnToNorm[y_]:=Join@@Table[ConstantArray[i,y[[i]]],{i,Length[y]}];
    facs[n_]:=If[n<=1,{{}},Join@@Table[Map[Prepend[#,d]&,Select[facs[n/d],Min@@#>=d&]],{d,Rest[Divisors[n]]}]];
    Table[Length[facs[Times@@Prime/@ptnToNorm[stc[n]]]],{n,0,30}]

Formula

a(n) = A001055(A057335(n)).

A329357 Numbers whose reversed binary expansion has co-Lyndon factorization of length 2.

Original entry on oeis.org

2, 3, 5, 9, 11, 17, 19, 23, 33, 35, 37, 39, 43, 47, 65, 67, 69, 71, 75, 79, 83, 87, 95, 129, 131, 133, 135, 137, 139, 143, 147, 149, 151, 155, 159, 163, 167, 171, 175, 183, 191, 257, 259, 261, 263, 265, 267, 271, 275, 277, 279, 283, 287, 291, 293, 295, 299
Offset: 1

Views

Author

Gus Wiseman, Nov 12 2019

Keywords

Comments

First differs from A329327 in lacking 77 and having 83.
The co-Lyndon product of two or more finite sequences is defined to be the lexicographically minimal sequence obtainable by shuffling the sequences together. For example, the co-Lyndon product of (231) and (213) is (212313), the product of (221) and (213) is (212213), and the product of (122) and (2121) is (1212122). A co-Lyndon word is a finite sequence that is prime with respect to the co-Lyndon product. Equivalently, a co-Lyndon word is a finite sequence that is lexicographically strictly greater than all of its cyclic rotations. Every finite sequence has a unique (orderless) factorization into co-Lyndon words, and if these factors are arranged in a certain order, their concatenation is equal to their co-Lyndon product. For example, (1001) has sorted co-Lyndon factorization (1)(100).

Examples

			The reversed binary expansion of each term together with their co-Lyndon factorizations:
   2:      (01) = (0)(1)
   3:      (11) = (1)(1)
   5:     (101) = (10)(1)
   9:    (1001) = (100)(1)
  11:    (1101) = (110)(1)
  17:   (10001) = (1000)(1)
  19:   (11001) = (1100)(1)
  23:   (11101) = (1110)(1)
  33:  (100001) = (10000)(1)
  35:  (110001) = (11000)(1)
  37:  (101001) = (10100)(1)
  39:  (111001) = (11100)(1)
  43:  (110101) = (11010)(1)
  47:  (111101) = (11110)(1)
  65: (1000001) = (100000)(1)
  67: (1100001) = (110000)(1)
  69: (1010001) = (101000)(1)
  71: (1110001) = (111000)(1)
  75: (1101001) = (110100)(1)
  79: (1111001) = (111100)(1)
		

Crossrefs

Positions of 2's in A329326.
Binary co-Lyndon words are counted by A001037 and ranked by A329318.
Length of the co-Lyndon factorization of the binary expansion is A329312.

Programs

  • Mathematica
    colynQ[q_]:=Array[Union[{RotateRight[q,#],q}]=={RotateRight[q,#],q}&,Length[q]-1,1,And];
    colynfac[q_]:=If[Length[q]==0,{},Function[i,Prepend[colynfac[Drop[q,i]],Take[q,i]]]@Last[Select[Range[Length[q]],colynQ[Take[q,#]]&]]];
    Select[Range[100],Length[colynfac[Reverse[IntegerDigits[#,2]]]]==2&]

A329359 Irregular triangle read by rows where row n gives the lengths of the factors in the co-Lyndon factorization of the binary expansion of n.

Original entry on oeis.org

1, 2, 1, 1, 3, 2, 1, 3, 1, 1, 1, 4, 3, 1, 2, 2, 2, 1, 1, 4, 3, 1, 4, 1, 1, 1, 1, 5, 4, 1, 3, 2, 3, 1, 1, 5, 2, 2, 1, 2, 3, 2, 1, 1, 1, 5, 4, 1, 5, 3, 1, 1, 5, 4, 1, 5, 1, 1, 1, 1, 1, 6, 5, 1, 4, 2, 4, 1, 1, 3, 3, 3, 2, 1, 3, 3, 3, 1, 1, 1, 6, 5, 1, 2, 2, 2, 2
Offset: 1

Views

Author

Gus Wiseman, Nov 12 2019

Keywords

Comments

The co-Lyndon product of two or more finite sequences is defined to be the lexicographically minimal sequence obtainable by shuffling the sequences together. For example, the co-Lyndon product of (231) and (213) is (212313), the product of (221) and (213) is (212213), and the product of (122) and (2121) is (1212122). A co-Lyndon word is a finite sequence that is prime with respect to the co-Lyndon product. Equivalently, a co-Lyndon word is a finite sequence that is lexicographically strictly greater than all of its cyclic rotations. Every finite sequence has a unique (orderless) factorization into co-Lyndon words, and if these factors are arranged in a certain order, their concatenation is equal to their co-Lyndon product. For example, (1001) has sorted co-Lyndon factorization (1)(100).

Examples

			Triangle begins:
   1: (1)       21: (221)      41: (51)       61: (51)
   2: (2)       22: (23)       42: (222)      62: (6)
   3: (11)      23: (2111)     43: (2211)     63: (111111)
   4: (3)       24: (5)        44: (24)       64: (7)
   5: (21)      25: (41)       45: (231)      65: (61)
   6: (3)       26: (5)        46: (24)       66: (52)
   7: (111)     27: (311)      47: (21111)    67: (511)
   8: (4)       28: (5)        48: (6)        68: (43)
   9: (31)      29: (41)       49: (51)       69: (421)
  10: (22)      30: (5)        50: (6)        70: (43)
  11: (211)     31: (11111)    51: (411)      71: (4111)
  12: (4)       32: (6)        52: (6)        72: (7)
  13: (31)      33: (51)       53: (51)       73: (331)
  14: (4)       34: (42)       54: (33)       74: (322)
  15: (1111)    35: (411)      55: (3111)     75: (3211)
  16: (5)       36: (33)       56: (6)        76: (34)
  17: (41)      37: (321)      57: (51)       77: (331)
  18: (32)      38: (33)       58: (6)        78: (34)
  19: (311)     39: (3111)     59: (411)      79: (31111)
  20: (5)       40: (6)        60: (6)        80: (7)
For example, 45 has binary expansion (101101), with co-Lyndon factorization (10)(110)(1), so row n = 45 is (2,3,1).
		

Crossrefs

Row lengths are A329312.
Row sums are A070939.
Positions of rows of length 1 are A275692.
The non-"co" version is A329314.
Binary co-Lyndon words are counted by A001037 and ranked by A329318.

Programs

  • Mathematica
    colynQ[q_]:=Array[Union[{RotateRight[q,#],q}]=={RotateRight[q,#],q}&,Length[q]-1,1,And];
    colynfac[q_]:=If[Length[q]==0,{},Function[i,Prepend[colynfac[Drop[q,i]],Take[q,i]]]@Last[Select[Range[Length[q]],colynQ[Take[q,#]]&]]];
    Table[Length/@colynfac[If[n==0,{},IntegerDigits[n,2]]],{n,30}]
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