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.

Previous Showing 11-19 of 19 results.

A329865 Numbers whose binary expansion has the same runs-resistance as cuts-resistance.

Original entry on oeis.org

0, 8, 12, 14, 17, 24, 27, 28, 35, 36, 39, 47, 49, 51, 54, 57, 61, 70, 73, 78, 80, 99, 122, 130, 156, 175, 184, 189, 190, 198, 204, 207, 208, 215, 216, 226, 228, 235, 243, 244, 245, 261, 271, 283, 295, 304, 313, 321, 322, 336, 352, 367, 375, 378, 379, 380, 386
Offset: 1

Views

Author

Gus Wiseman, Nov 23 2019

Keywords

Comments

For the operation of taking the sequence of run-lengths of a finite sequence, runs-resistance is defined to be the number of applications required to reach a singleton.
For the operation of shortening all runs by 1, cuts-resistance is defined to be the number of applications required to reach an empty word.

Examples

			The sequence of terms together with their binary expansions begins:
    0:
    8:      1000
   12:      1100
   14:      1110
   17:     10001
   24:     11000
   27:     11011
   28:     11100
   35:    100011
   36:    100100
   39:    100111
   47:    101111
   49:    110001
   51:    110011
   54:    110110
   57:    111001
   61:    111101
   70:   1000110
   73:   1001001
   78:   1001110
   80:   1010000
For example, 36 has runs-resistance 3 because we have (100100) -> (1212) -> (1111) -> (4), while the cuts-resistance is also 3 because we have (100100) -> (00) -> (0) -> ().
Similarly, 57 has runs-resistance 3 because we have (111001) -> (321) -> (111) -> (3), while the cuts-resistance is also 3 because we have (111001) -> (110) -> (1) -> ().
		

Crossrefs

Positions of 0's in A329867.
The version for runs-resistance equal to cuts-resistance minus 1 is A329866.
Compositions with runs-resistance equal to cuts-resistance are A329864.
Runs-resistance of binary expansion is A318928.
Cuts-resistance of binary expansion is A319416.
Compositions counted by runs-resistance are A329744.
Compositions counted by cuts-resistance are A329861.
Binary words counted by runs-resistance are A319411 and A329767.
Binary words counted by cuts-resistance are A319421 and A329860.

Programs

  • Mathematica
    runsres[q_]:=Length[NestWhileList[Length/@Split[#]&,q,Length[#]>1&]]-1;
    degdep[q_]:=Length[NestWhileList[Join@@Rest/@Split[#]&,q,Length[#]>0&]]-1;
    Select[Range[0,100],#==0||runsres[IntegerDigits[#,2]]==degdep[IntegerDigits[#,2]]&]

A319420 Irregular triangle read by rows: row n lists the cuts-resistances of the 2^n binary vectors of length n.

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Sep 22 2018

Keywords

Comments

The cuts-resistance of a vector is defined in A319416. The 2^n vectors of length n are taken in lexicographic order.
Note that here the vectors can begin with either 0 or 1, whereas in A319416 only vectors beginning with 1 are considered (since there we are considering binary representations of numbers).
Conjecture: The row sums, halved, appear to match A189391.

Examples

			Triangle begins:
0,
1,1,
2,1,1,2,
3,2,1,2,2,1,2,3,
4,3,2,2,2,1,2,3,3,2,1,2,2,2,3,4,
5,4,3,3,3,2,2,3,3,2,1,2,2,2,3,4,4,3,2,2,2,1,2,3,3,2,2,2,3,3,3,4,5,
...
		

Crossrefs

Keeping the first digit gives A319416.
Positions of 1's are the terms > 1 of A061547 and A086893, all minus 1.
The version for runs-resistance is A329870.
Compositions counted by cuts-resistance are A329861.
Binary words counted by cuts-resistance are A319421 or A329860.

Programs

  • Mathematica
    degdep[q_]:=Length[NestWhileList[Join@@Rest/@Split[#]&,q,Length[#]>0&]]-1;
    Table[degdep[Rest[IntegerDigits[n,2]]],{n,0,50}] (* Gus Wiseman, Nov 25 2019 *)

A329750 Triangle read by rows where T(n,k) is the number of compositions of n >= 1 with runs-resistance n - k, 1 <= k <= n.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 2, 3, 2, 1, 2, 6, 6, 1, 1, 0, 4, 9, 15, 3, 1, 0, 2, 16, 22, 22, 1, 1, 0, 0, 8, 37, 38, 41, 3, 1, 0, 0, 0, 26, 86, 69, 72, 2, 1, 0, 0, 0, 2, 78, 175, 124, 129, 3, 1, 0, 0, 0, 0, 14, 202, 367, 226, 213, 1, 1, 0, 0, 0, 0, 0, 52, 469, 750, 376, 395, 5, 1
Offset: 1

Views

Author

Gus Wiseman, Nov 21 2019

Keywords

Comments

A composition of n is a finite sequence of positive integers with sum n.
For the operation of taking the sequence of run-lengths of a finite sequence, runs-resistance is defined as the number of applications required to reach a singleton.

Examples

			Triangle begins:
   1
   1   1
   2   1   1
   2   3   2   1
   2   6   6   1   1
   0   4   9  15   3   1
   0   2  16  22  22   1   1
   0   0   8  37  38  41   3   1
   0   0   0  26  86  69  72   2   1
   0   0   0   2  78 175 124 129   3   1
   0   0   0   0  14 202 367 226 213   1   1
   0   0   0   0   0  52 469 750 376 395   5   1
Row n = 6 counts the following compositions:
  (1,1,3,1)    (1,1,4)      (1,5)      (3,3)          (6)
  (1,3,1,1)    (4,1,1)      (2,4)      (2,2,2)
  (1,1,1,2,1)  (1,1,1,3)    (4,2)      (1,1,1,1,1,1)
  (1,2,1,1,1)  (1,2,2,1)    (5,1)
               (2,1,1,2)    (1,2,3)
               (3,1,1,1)    (1,3,2)
               (1,1,1,1,2)  (1,4,1)
               (1,1,2,1,1)  (2,1,3)
               (2,1,1,1,1)  (2,3,1)
                            (3,1,2)
                            (3,2,1)
                            (1,1,2,2)
                            (1,2,1,2)
                            (2,1,2,1)
                            (2,2,1,1)
		

Crossrefs

Row sums are A000079.
Column sums are A329768.
The version with rows reversed is A329744.

Programs

  • Mathematica
    runsres[q_]:=Length[NestWhileList[Length/@Split[#]&,q,Length[#]>1&]]-1;
    Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],runsres[#]==n-k&]],{n,10},{k,n}]

A329867 Runs-resistance minus cuts-resistance of the binary expansion of n.

Original entry on oeis.org

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

Views

Author

Gus Wiseman, Nov 23 2019

Keywords

Comments

For the operation of taking the sequence of run-lengths of a finite sequence, runs-resistance is defined to be the number of applications required to reach a singleton.
For the operation of shortening all runs by 1, cuts-resistance is defined to be the number of applications required to reach an empty word.

Examples

			The sequence of binary expansions together with their runs-resistances and cuts-resistances, and their differences, begins:
   0      (): 0 - 0 =  0
   1     (1): 0 - 1 = -1
   2    (10): 2 - 1 =  1
   3    (11): 1 - 2 = -1
   4   (100): 3 - 2 =  1
   5   (101): 2 - 1 =  1
   6   (110): 3 - 2 =  1
   7   (111): 1 - 3 = -2
   8  (1000): 3 - 3 =  0
   9  (1001): 3 - 2 =  1
  10  (1010): 2 - 1 =  1
  11  (1011): 4 - 2 =  2
  12  (1100): 2 - 2 =  0
  13  (1101): 4 - 2 =  2
  14  (1110): 3 - 3 =  0
  15  (1111): 1 - 4 = -3
  16 (10000): 3 - 4 = -1
  17 (10001): 3 - 3 =  0
  18 (10010): 5 - 2 =  3
  19 (10011): 4 - 2 =  2
  20 (10100): 4 - 2 =  2
		

Crossrefs

Positions of 0's are A329865.
Positions of -1's are A329866.
Sorted positions of first appearances are A329868.
Compositions with runs-resistance equal to cuts-resistance are A329864.
Compositions with runs-resistance = cuts-resistance minus 1 are A329869.
Runs-resistance of binary expansion is A318928.
Cuts-resistance of binary expansion is A319416.
Compositions counted by runs-resistance are A329744.
Compositions counted by cuts-resistance are A329861.
Binary words counted by runs-resistance are A319411 and A329767.
Binary words counted by cuts-resistance are A319421 and A329860.

Programs

  • Mathematica
    runsres[q_]:=Length[NestWhileList[Length/@Split[#]&,q,Length[#]>1&]]-1;
    degdep[q_]:=Length[NestWhileList[Join@@Rest/@Split[#]&,q,Length[#]>0&]]-1;
    Table[If[n==0,0,runsres[IntegerDigits[n,2]]-degdep[IntegerDigits[n,2]]],{n,0,100}]

Formula

For n > 1, a(2^n) = 3 - n.
For n > 1, a(2^n - 1) = 1 - n.

A329866 Numbers whose binary expansion has its runs-resistance equal to its cuts-resistance minus 1.

Original entry on oeis.org

1, 3, 16, 30, 33, 48, 55, 56, 59, 60, 67, 68, 72, 79, 95, 97, 110, 112, 118, 120, 121, 125, 134, 135, 137, 143, 145, 158, 160, 195, 196, 219, 220, 225, 231, 241, 250, 258, 270, 280, 286, 291, 292, 315, 316, 351, 381, 382, 390, 391, 393, 399, 415, 416, 431, 432
Offset: 1

Views

Author

Gus Wiseman, Nov 23 2019

Keywords

Comments

For the operation of taking the sequence of run-lengths of a finite sequence, runs-resistance is defined to be the number of applications required to reach a singleton.
For the operation of shortening all runs by 1, cuts-resistance is defined to be the number of applications required to reach an empty word.

Examples

			The sequence of terms together with their binary expansions begins:
    1:         1
    3:        11
   16:     10000
   30:     11110
   33:    100001
   48:    110000
   55:    110111
   56:    111000
   59:    111011
   60:    111100
   67:   1000011
   68:   1000100
   72:   1001000
   79:   1001111
   95:   1011111
   97:   1100001
  110:   1101110
  112:   1110000
  118:   1110110
  120:   1111000
For example, 79 has runs-resistance 3 because we have (1001111) -> (124) -> (111) -> (3), while the cuts-resistance is 4 because we have (1001111) -> (0111) -> (11) -> (1) -> (), so 79 is in the sequence.
		

Crossrefs

Positions of -1's in A329867.
The version for runs-resistance equal to cuts-resistance is A329865.
Compositions with runs-resistance equal to cuts-resistance are A329864.
Compositions with runs-resistance = cuts-resistance minus 1 are A329869.
Runs-resistance of binary expansion is A318928.
Cuts-resistance of binary expansion is A319416.
Compositions counted by runs-resistance are A329744.
Compositions counted by cuts-resistance are A329861.
Binary words counted by runs-resistance are A319411 and A329767.
Binary words counted by cuts-resistance are A319421 and A329860.

Programs

  • Mathematica
    runsres[q_]:=Length[NestWhileList[Length/@Split[#]&,q,Length[#]>1&]]-1;
    degdep[q_]:=Length[NestWhileList[Join@@Rest/@Split[#]&,q,Length[#]>0&]]-1;
    Select[Range[100],runsres[IntegerDigits[#,2]]-degdep[IntegerDigits[#,2]]==-1&]

A329868 Sorted positions of first appearances in A329867 (difference between the runs-resistance and the cuts-resistance of binary expansion) of each element in the image.

Original entry on oeis.org

0, 1, 2, 7, 11, 15, 18, 31, 63, 75, 127, 255, 511, 1023, 1234, 2047, 4095, 8191, 9638, 16383, 32767, 65535, 131071, 262143, 524287, 1048575, 2097151, 4194303, 8388607
Offset: 1

Views

Author

Gus Wiseman, Nov 23 2019

Keywords

Comments

For the operation of taking the sequence of run-lengths of a finite sequence, runs-resistance is defined to be the number of applications required to reach a singleton.
For the operation of shortening all runs by 1, cuts-resistance is defined to be the number of applications required to reach an empty word.

Examples

			The sequence of terms together with their binary expansions begins:
      0:
      1:                1
      2:               10
      7:              111
     11:             1011
     15:             1111
     18:            10010
     31:            11111
     63:           111111
     75:          1001011
    127:          1111111
    255:         11111111
    511:        111111111
   1023:       1111111111
   1234:      10011010010
   2047:      11111111111
   4095:     111111111111
   8191:    1111111111111
   9638:   10010110100110
  16383:   11111111111111
  32767:  111111111111111
  65535: 1111111111111111
		

Crossrefs

Sorted positions of first appearances in A329867.
Compositions with runs-resistance equal to cuts-resistance are A329864.
Runs-resistance of binary expansion is A318928.
Cuts-resistance of binary expansion is A319416.
Compositions counted by runs-resistance are A329744.
Compositions counted by cuts-resistance are A329861.
Binary words counted by runs-resistance are A319411 and A329767.
Binary words counted by cuts-resistance are A319421 and A329860.

Programs

  • Mathematica
    runsres[q_]:=Length[NestWhileList[Length/@Split[#]&,q,Length[#]>1&]]-1;
    degdep[q_]:=Length[NestWhileList[Join@@Rest/@Split[#]&,q,Length[#]>0&]]-1;
    das=Table[If[n==0,0,runsres[IntegerDigits[n,2]]-degdep[IntegerDigits[n,2]]],{n,0,1000000}];
    Table[Position[das,i][[1,1]]-1,{i,First/@Gather[das]}]

A329870 Runs-resistance of the binary expansion of n without the first digit.

Original entry on oeis.org

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

Views

Author

Gus Wiseman, Nov 25 2019

Keywords

Comments

For the operation of taking the sequence of run-lengths of a finite sequence, runs-resistance is defined to be the number of applications required to reach a singleton.

Examples

			Minimal representatives with each image are:
    2: (0)
    4: (0,0) -> (2)
    5: (0,1) -> (1,1) -> (2)
    9: (0,0,1) -> (2,1) -> (1,1) -> (2)
   18: (0,0,1,0) -> (2,1,1) -> (1,2) -> (1,1) -> (2)
   41: (0,1,0,0,1) -> (1,1,2,1) -> (2,1,1) -> (1,2) -> (1,1) -> (2)
  150: (0,0,1,0,1,1,0) -> (2,1,1,2,1) -> (1,2,1,1) -> (1,1,2) -> (2,1) -> (1,1) -> (2)
		

Crossrefs

Keeping the first digit gives A318928.
Cuts-resistance is A319420.
Compositions counted by runs-resistance are A329744.
Binary words counted by runs-resistance are A319411 and A329767.

Programs

  • Mathematica
    Table[Length[NestWhileList[Length/@Split[#]&,Rest[IntegerDigits[n,2]],Length[#]>1&]]-1,{n,2,100}]

A329743 Number of compositions of n with runs-resistance n - 3.

Original entry on oeis.org

0, 0, 0, 1, 2, 6, 9, 16, 8
Offset: 0

Views

Author

Gus Wiseman, Nov 21 2019

Keywords

Comments

A composition of n is a finite sequence of positive integers with sum n.
For the operation of taking the sequence of run-lengths of a finite sequence, runs-resistance is defined as the number of applications required to reach a singleton.

Examples

			The a(3) = 1 through a(8) = 8 compositions:
  (3)  (22)    (14)   (114)    (1123)    (12113)
       (1111)  (23)   (411)    (1132)    (12212)
               (32)   (1113)   (1141)    (13112)
               (41)   (1221)   (1411)    (21131)
               (131)  (2112)   (2122)    (21221)
               (212)  (3111)   (2212)    (31121)
                      (11112)  (2311)    (121112)
                      (11211)  (3211)    (211121)
                      (21111)  (11131)
                               (11212)
                               (11221)
                               (12211)
                               (13111)
                               (21211)
                               (111121)
                               (121111)
For example, repeatedly taking run-lengths starting with (1,2,1,1,3) gives (1,2,1,1,3) -> (1,1,2,1) -> (2,1,1) -> (1,2) -> (1,1) -> (2), which is 5 steps, and 5 = 8 - 3, so (1,2,1,1,3) is counted under a(8).
		

Crossrefs

Column k = n - 3 of A329744.
Column k = 3 of A329750.
Compositions with runs-resistance 2 are A329745.

Programs

  • Mathematica
    runsres[q_]:=If[Length[q]==1,0,Length[NestWhileList[Length/@Split[#]&,q,Length[#]>1&]]-1];
    Table[Length[Select[Join@@Permutations/@IntegerPartitions[n],runsres[#]==n-3&]],{n,10}]

A329768 Number of finite sequences of positive integers whose sum minus runs-resistance is n.

Original entry on oeis.org

8, 17, 42, 104, 242, 541, 1212, 2664, 5731, 12314
Offset: 1

Views

Author

Gus Wiseman, Nov 21 2019

Keywords

Comments

A composition of n is a finite sequence of positive integers with sum n.
For the operation of taking the sequence of run-lengths of a finite sequence, runs-resistance is defined as the number of applications required to reach a singleton.

Examples

			The a(1) = 8 and a(2) = 17 compositions whose sum minus runs-resistance is n:
  (1)        (2)
  (1,1)      (1,3)
  (1,2)      (3,1)
  (2,1)      (1,1,1)
  (1,1,2)    (1,1,3)
  (2,1,1)    (1,2,1)
  (1,1,2,1)  (1,2,2)
  (1,2,1,1)  (2,2,1)
             (3,1,1)
             (1,1,1,2)
             (1,1,3,1)
             (1,3,1,1)
             (2,1,1,1)
             (1,1,1,2,1)
             (1,2,1,1,1)
             (1,2,1,1,2)
             (2,1,1,2,1)
		

Crossrefs

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