A009807 Expansion of tanh(tan(sin(x))).

1, -1, -7, 167, 1553, -238481, 4553, 1254638551, -35872740703, -17157807788193, 1532562286297113, 488815558185860999, -101586398550375052879, -24471009470566855107377, 10960094402513781594777321

Offset

0,3

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Tanh[Tan[Sin[x]]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Oct 24 2016 *)

Crossrefs

Sequence in context: A012689 A098632 A192275 * A220991 A165388 A124126

Adjacent sequences: A009804 A009805 A009806 * A009808 A009809 A009810

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 24 2016

Status

approved