A024282 Expansion of e.g.f. tanh(x)*sin(sin(x))/2, even powers only.

0, 1, -8, 124, -3168, 121232, -6609664, 491033408, -47878820864, 5942382135552, -915386669357056, 171409533142952960, -38347910567533715456, 10102227232688591245312, -3095277524018668920373248

Offset

0,3

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..100

Formula

a(n) ~ (-1)^(n+1) * sinh(sinh(Pi/2)) * 2^(2*n+1) * (2*n)! / Pi^(2*n+1). - Vaclav Kotesovec, Apr 20 2014

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Tanh[x]Sin[Sin[x]]/2, {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Oct 20 2013 *)

Prog

(PARI) A024282=n->{my(t=x+O(x^(2*n+!n))); polcoeff(tanh(t)*sin(sin(t)), n*2, x)/2*(2*n)!} \\ M. F. Hasler, Feb 09 2014

Crossrefs

Cf. A009833.

Sequence in context: A069459 A254125 A371298 * A340888 A231638 A065082

Adjacent sequences: A024279 A024280 A024281 * A024283 A024284 A024285

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program replaced by Harvey P. Dale, Oct 20 2013

Clarified definition, Joerg Arndt, Feb 09 2014

Status

approved