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A009665 E.g.f. tan(sin(x))*sin(x) (even powers only). 1
0, 2, 0, -32, -640, 1024, 661504, 25305088, -948699136, -216606572544, -10006005547008, 2013855760777216, 462400685741178880, 10633324821284388864, -16549579084211148554240 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..14.

FORMULA

a(n)=sum(k=1..n, ((sum(j=1..2*k-1, j!*(-1)^(j)*2^(2*n-j)*stirling2(2*k-1,j)))*sum(i=0..k, (i-k)^(2*n)*binomial(2*k,i)*(-1)^(n-i)))/((2*k-1)!)). - Vladimir Kruchinin, Jun 29 2011

PROG

(Maxima)

a(n):=sum(((sum(j!*(-1)^(j)*2^(2*n-j)*stirling2(2*k-1, j), j, 1, 2*k-1))*sum((i-k)^(2*n)*binomial(2*k, i)*(-1)^(n-i), i, 0, k))/((2*k-1)!), k, 1, n); /* Vladimir Kruchinin, Jun 29 2011 */

CROSSREFS

Sequence in context: A156473 A156504 A340545 * A053552 A009548 A172388

Adjacent sequences: A009662 A009663 A009664 * A009666 A009667 A009668

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

STATUS

approved

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Last modified December 2 12:07 EST 2022. Contains 358493 sequences. (Running on oeis4.)