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A009446 E.g.f. sin(x*cos(x)) (odd powers only) 5
1, -4, 36, -848, 23824, -871872, 44942912, -2860930816, 213856723200, -19099352929280, 2010469524579328, -242177953175506944, 32998102512641970176, -5069553933584348397568, 870871673923373487243264 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

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

FORMULA

a(n)=(-1)^(n)*sum(k=0..n, binomial(2*n+1,2*k+1)*((sum(i=0..k, (2*k+1-2*i)^(2*n-2*k)*binomial(2*k+1,i))))/(2^(2*k))). - Vladimir Kruchinin, Jun 18 2011

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Sin[x Cos[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Oct 04 2017 *)

PROG

(Maxima)

a(n):=(-1)^(n)*sum(binomial(2*n+1, 2*k+1)*((sum((2*k+1-2*i)^(2*n-2*k)*binomial(2*k+1, i), i, 0, ((k)))))/(2^(2*k)), k, 0, n); /* Vladimir Kruchinin, Jun 18 2011 */

CROSSREFS

Sequence in context: A145565 A214669 A126152 * A134052 A127901 A061742

Adjacent sequences:  A009443 A009444 A009445 * A009447 A009448 A009449

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

STATUS

approved

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Last modified August 26 05:23 EDT 2019. Contains 326328 sequences. (Running on oeis4.)