A009741 Expansion of tan(x)*sin(sinh(x)).

0, 2, 8, 48, 832, 34304, 1992704, 149382912, 14491045888, 1792468533248, 275860960329728, 51650706246205440, 11555611726669152256, 3044203421408056377344, 932732257836665756450816

Offset

0,2

Links

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

Formula

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Tan[x]Sin[Sinh[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Jun 08 2025 *)
nn = 20; Table[(CoefficientList[Series[Sin[Sinh[x]]*Tan[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: A192411 A179563 A079802 * A322309 A009745 A009751

Adjacent sequences: A009738 A009739 A009740 * A009742 A009743 A009744

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested Mar 15 1997 by Olivier Gérard.

First Mathematica program replaced by Harvey P. Dale, Jun 08 2025

Status

approved