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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A089839 Array A(x,y): (read as A(0,0), A(1,0), A(0,1), A(2,0), A(1,1), A(0,2), A(3,0), A(2,1), A(1,2), A(0,3),...) Position of the composition A089840[y] o A089840[x] in the table A089840.

Original entry on oeis.org

0, 1, 1, 2, 0, 2, 3, 14, 19, 3, 4, 15, 0, 21, 4, 5, 16, 6, 4, 17, 5, 6, 13, 5, 0, 3, 18, 6, 7, 12, 4, 2, 5, 6, 20, 7, 8, 21, 3, 6, 6, 4, 5, 15, 8, 9, 18, 1654606, 5, 2, 3, 2, 1654137, 13, 9, 10, 17, 1655095, 1654694, 0, 0, 0, 1654694, 1654255, 16, 10
Offset: 0

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Author

Antti Karttunen, Dec 05 2003

Keywords

Comments

This is a "multiplication table" of an infinite enumerable group. Each row and column is a permutation of A001477.

Examples

			A(2,1)=14 because A089840[2] = A072796, A089840[1] = A069770 and the composition A069770 o A072796 (here the right hand side permutation acts first) yields A073269 = A089840[14]. Similarly A(2,2)=0, as A089840[2] = A072796, which being an involution, yields A001477 (= A089840[0]) when "squared".
		

Crossrefs

Column 1: A089837, row 1: A089838, the main diagonal: A089841.

A261219 Main diagonal of A261216: a(n) = A261216(n,n).

Original entry on oeis.org

0, 0, 0, 5, 0, 3, 0, 0, 14, 16, 22, 20, 0, 19, 8, 20, 0, 7, 0, 13, 0, 7, 10, 16, 0, 0, 0, 5, 0, 3, 54, 54, 60, 65, 66, 69, 84, 90, 78, 95, 84, 81, 114, 108, 114, 107, 102, 111, 0, 0, 74, 76, 100, 98, 30, 30, 78, 83, 102, 105, 0, 19, 26, 45, 100, 119, 0, 13, 74, 87, 28, 41, 0, 97, 50, 98, 0, 49, 0, 97, 26, 117, 22, 47, 36, 108, 60, 113, 36, 63, 0, 25, 50, 33, 10, 59, 0, 73, 0, 49, 52
Offset: 0

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Author

Antti Karttunen, Aug 26 2015

Keywords

Comments

Equally: main diagonal of A261217.
For permutation p, which has rank n in permutation list A060117, a(n) gives the rank of the "square" of that permutation (obtained by composing it with itself as: q(i) = p(p(i))) in the same list. Equally, if permutation p has rank n in the order used in list A060118, a(n) gives the rank of the p*p in that same list. Thus zeros (which mark the identity permutation, with rank 0 in both orders) occur at positions where the permutations of A060117 (equally: of A060118) are involutions, listed by A261220.

Crossrefs

Main diagonal of A261216 and A261217.
Cf. A261220 (the positions of zeros).
Cf. also A261099, A089841.
Related permutations: A060119, A060126.

Formula

a(n) = A261216(n,n) = A261217(n,n).
By conjugating a similar sequence:
a(n) = A060126(A261099(A060119(n))).
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