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A032291 Shifts left 2 places under "DIK" (bracelet, indistinct, unlabeled) transform. 1
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 (list; graph; refs; listen; history; text; internal format)
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: A215067 A008928 A124343 * A063687 A002988 A138347

Adjacent sequences:  A032288 A032289 A032290 * A032292 A032293 A032294

KEYWORD

nonn,eigen

AUTHOR

Christian G. Bower

STATUS

approved

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Last modified October 22 11:13 EDT 2018. Contains 316438 sequences. (Running on oeis4.)