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A009516 Expansion of sin(tan(x)/cos(x)). 0
1, 4, 12, -1472, -159792, -16362304, -1834702400, -218477736448, -23399883425536, -225490426670080, 1498513205985651712, 985137918553296764928, 536781621147089121005568, 285950922368074600238661632 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..13.

MATHEMATICA

Sin[ Tan[ x ]/Cos[ x ] ] (* Odd Part *)

PROG

(Maxima)

a(n):=4*sum(((-1)^(m)*sum((binomial(m+k-1, 2*m)*sum((2*i-2*k+1)^(2*n+1)*binomial(2*k-1, i)*(-1)^(i-n+k), i, 0, k-1/2))/2^(2*k), k, m+1, n+1))/(2*m+1)!, m, 0, n); /* Vladimir Kruchinin, Jun 23 2011 */

CROSSREFS

Sequence in context: A085116 A104129 A144631 * A266500 A146210 A024248

Adjacent sequences:  A009513 A009514 A009515 * A009517 A009518 A009519

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

STATUS

approved

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Last modified January 24 21:49 EST 2022. Contains 350565 sequences. (Running on oeis4.)