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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A129599 Prime-factorization encoded partition code for the Łukasiewicz-word, variant of A129593.

Original entry on oeis.org

1, 3, 25, 25, 343, 35, 35, 343, 35, 14641, 847, 847, 847, 55, 847, 55, 847, 14641, 847, 55, 847, 847, 55, 371293, 24167, 24167, 1573, 1183, 24167, 1183, 1573, 24167, 1183, 1183, 1183, 1183, 65, 24167, 1183, 1183, 1183, 65, 1573, 1183, 24167
Offset: 0

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Author

Antti Karttunen, May 01 2007

Keywords

Comments

In addition to all the automorphisms whose signature permutation satisfies the more restricted condition A127301(SP(n)) = A127301(n) for all n, there are also general tree-rotating automorphisms like *A057501, *A057502, *A069771 and *A069772 that satisfy also the condition A129599(SP(n)) = A129599(n) for all n. However, in contrast to A129593 this is not invariant under the automorphism *A072797. A000041(n) distinct values (seem to) occur in each range [A014137(n)..A014138(n)].

Examples

			The terms A079436(5), A079436(6) and A079436(8) are 2010, 2100 and 1110. After adding one to each number except the first one we get 2121, 2211 and 1221, each one which produces partition 1+1+2+2. Converting it to prime-exponents like explained in A129595, we get 2^0 * 3^0 * 5^1 * 7^1 = 35, thus a(5) = a(6) = a(8) = 35.

Links

Crossrefs

Variant: A129593.

Formula

Construction: add one to each number of the Łukasiewicz-word of a general plane tree encoded by A014486(n) (i.e. A079436(n)) except the first number, sort the numbers into ascending order and interpreting it as a partition of a natural number, encode it in the manner explained in A129595.

A347539 Matula-Goebel number of the n-th tree in Beyer and Hedetniemi's rooted tree iteration (A346913).

Original entry on oeis.org

1, 2, 3, 4, 5, 7, 6, 8, 11, 17, 13, 10, 19, 14, 9, 12, 16, 31, 59, 41, 29, 22, 67, 43, 34, 23, 37, 26, 15, 20, 53, 38, 21, 28, 18, 24, 32, 127, 277, 179, 109, 79, 62, 331, 191, 139, 118, 83, 157, 101, 82, 47, 71, 58, 33, 44, 241, 163, 134, 73, 107, 86, 51, 68
Offset: 1

Views

Author

Kevin Ryde, Sep 06 2021

Keywords

Comments

This sequence is a permutation of the natural numbers, with inverse A347540.

Examples

			For n=33, row 33 of A346913 is levels sequence 1,2,3,3,2,3 which is the following tree,
  root      21          a(33) = 21 Matula-Goebel number
            |  \        (being prime(4)*prime(2) = 21)
  children  4    2
            |\   |
            1 1  1

Links

Crossrefs

Cf. A346913, A347540 (inverse), A061773, A127301.

A358550 Depth of the ordered rooted tree with binary encoding A014486(n).

Original entry on oeis.org

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

Views

Author

Gus Wiseman, Nov 22 2022

Keywords

Comments

The binary encoding of an ordered tree (A014486) is obtained by replacing the internal left and right brackets with 0's and 1's, thus forming a binary number.

Examples

			The first few rooted trees in binary encoding are:
    0: o
    2: (o)
   10: (oo)
   12: ((o))
   42: (ooo)
   44: (o(o))
   50: ((o)o)
   52: ((oo))
   56: (((o)))
  170: (oooo)
  172: (oo(o))
  178: (o(o)o)
  180: (o(oo))
  184: (o((o)))

Crossrefs

Positions of first appearances are A014137.
Leaves of the ordered tree are counted by A057514, standard A358371.
Branches of the ordered tree are counted by A057515.
Edges of the ordered tree are counted by A072643.
The Matula-Goebel number of the ordered tree is A127301.
Positions of 2's are A155587, indices of A020988.
The standard ranking of the ordered tree is A358523.
Nodes of the ordered tree are counted by A358551, standard A358372.
For standard instead of binary encoding we have A358379.
A000108 counts ordered rooted trees, unordered A000081.
A014486 lists all binary encodings.
Cf. A001263, A057122, A358373, A358505, A358524.

Programs

  • Mathematica
    binbalQ[n_]:=n==0||Count[IntegerDigits[n,2],0]==Count[IntegerDigits[n,2],1]&&And@@Table[Count[Take[IntegerDigits[n,2],k],0]<=Count[Take[IntegerDigits[n,2],k],1],{k,IntegerLength[n,2]}];
bint[n_]:=If[n==0,{},ToExpression[StringReplace[StringReplace[ToString[IntegerDigits[n,2]/.{1->"{",0->"}"}],","->""],"} {"->"},{"]]];
Table[Depth[bint[k]]-1,{k,Select[Range[0,1000],binbalQ]}]

A358551 Number of nodes in the ordered rooted tree with binary encoding A014486(n).

Original entry on oeis.org

1, 2, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
Offset: 1

Views

Author

Gus Wiseman, Nov 22 2022

Keywords

Comments

The binary encoding of an ordered tree (A014486) is obtained by replacing the internal left and right brackets with 0's and 1's, thus forming a binary number.

Examples

			The first few rooted trees in binary encoding are:
    0: o
    2: (o)
   10: (oo)
   12: ((o))
   42: (ooo)
   44: (o(o))
   50: ((o)o)
   52: ((oo))
   56: (((o)))
  170: (oooo)
  172: (oo(o))
  178: (o(o)o)
  180: (o(oo))
  184: (o((o)))

Crossrefs

Run-lengths are A000108.
Binary encodings are listed by A014486.
Leaves of the ordered tree are counted by A057514, standard A358371.
Branches of the ordered tree are counted by A057515.
Edges of the ordered tree are counted by A072643.
The Matula-Goebel number of the ordered tree is A127301.
For standard instead of binary encoding we have A358372.
The standard ranking of the ordered tree is A358523.
Depth of the ordered tree is A358550, standard A358379.
Cf. A000081, A001263, A057122, A358373, A358505, A358524.

Programs

  • Mathematica
    binbalQ[n_]:=n==0||Count[IntegerDigits[n,2],0]==Count[IntegerDigits[n,2],1]&&And@@Table[Count[Take[IntegerDigits[n,2],k],0]<=Count[Take[IntegerDigits[n,2],k],1],{k,IntegerLength[n,2]}];
bint[n_]:=If[n==0,{},ToExpression[StringReplace[StringReplace[ToString[IntegerDigits[n,2]/.{1->"{",0->"}"}],","->""],"} {"->"},{"]]];
Table[Count[bint[k],_,{0,Infinity}],{k,Select[Range[0,10000],binbalQ]}]

Formula

a(n) = A072643(n) + 1.
Previous Showing 21-24 of 24 results.

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