A032291 Shifts left 2 places under "DIK" (bracelet, indistinct, unlabeled) transform.

1, 1, 1, 2, 3, 6, 10, 21, 38, 81, 160, 344, 716, 1571, 3390, 7548, 16740, 37778, 85338, 194894, 446208, 1028935, 2379730, 5531126, 12892778, 30162239, 70745300, 166403255, 392286953, 926915606, 2194450545, 5205237589

Offset

1,4

Links

Andrew Howroyd, Table of n, a(n) for n = 1..200

Prog

(PARI)
DIK(p, n)={(sum(d=1, n, eulerphi(d)/d*log(subst(1/(1+O(x*x^(n\d))-p), x, x^d))) + ((1+p)^2/(1-subst(p, x, x^2))-1)/2)/2}
seq(n)={my(p=1+O(x)); for(i=1, n\2, p=1+x+x*DIK(x*p, 2*i)); Vec(p+O(x^n))} \\ Andrew Howroyd, Jun 20 2018

Crossrefs

Sequence in context: A008928 A124343 A324407 * A063687 A359019 A002988

Adjacent sequences: A032288 A032289 A032290 * A032292 A032293 A032294

Keyword

nonn,eigen

Author

Christian G. Bower

Status

approved