

A009682


Expansion of tan(sinh(x))*sin(x).


1



0, 2, 8, 168, 6208, 365984, 31759232, 3799039104, 599327352832, 120551382086144, 30112348370954240, 9144842254707320832, 3318219571077818269696, 1417778434388262802202624
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OFFSET

0,2


LINKS

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


FORMULA

a(n) ~ (2*n)! * 4 * sin(arcsinh(Pi/2)) / (sqrt(4+Pi^2) * arcsinh(Pi/2)^(2*n+1)).  Vaclav Kotesovec, Jan 23 2015


MATHEMATICA

Tan[ Sinh[ x ] ]*Sin[ x ] (* Even Part *)
nn = 20; Table[(CoefficientList[Series[Sin[x]*Tan[Sinh[x]], {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* Vaclav Kotesovec, Jan 23 2015 *)


CROSSREFS

Sequence in context: A012540 A175538 A009606 * A076548 A167009 A105232
Adjacent sequences: A009679 A009680 A009681 * A009683 A009684 A009685


KEYWORD

nonn


AUTHOR

R. H. Hardin


EXTENSIONS

Extended and signs tested Mar 15 1997 by Olivier Gérard.


STATUS

approved



