login
A261099
Main diagonal of A261096.
7
0, 0, 0, 4, 3, 0, 0, 0, 12, 16, 23, 19, 8, 23, 0, 20, 0, 7, 16, 11, 15, 0, 7, 0, 0, 0, 0, 4, 3, 0, 48, 48, 60, 64, 71, 67, 86, 93, 74, 94, 74, 85, 116, 111, 119, 99, 108, 99, 30, 30, 86, 89, 112, 111, 0, 0, 78, 82, 107, 103, 0, 20, 26, 46, 96, 103, 15, 0, 41, 29, 78, 73, 60, 115, 38, 119, 38, 63, 56, 107, 0, 104, 0, 55, 26, 100, 0, 104, 19, 42, 33, 56, 11, 52, 0, 25
OFFSET
0,4
COMMENTS
Equally: main diagonal of A261097.
For permutation p, which has rank n in permutation list A055089 (A195663), 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. Thus zeros (which mark the identity permutation, with rank 0) occur at positions where the permutations of A055089/A195663 are involutions, listed by A014489.
LINKS
FORMULA
a(n) = A261096(n,n) = A261097(n,n).
By conjugating a similar sequence:
a(n) = A060119(A261219(A060126(n))).
CROSSREFS
Main diagonal of A261096 and A261097.
Cf. A014489 (the positions of zeros).
Cf. also A261219.
Related permutations: A060119, A060126.
Sequence in context: A293496 A290326 A284947 * A030120 A058878 A236289
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 26 2015
STATUS
approved