A024231 Expansion of tanh(tan(x))*sin(x)/2.

0, 1, -2, -21, -228, 5077, 631834, 37060863, 791278008, -198249695063, -43572627802442, -5264284574193645, -189769141997109804, 100566175129622055037, 26413749605638836403666

Offset

0,3

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Tanh[Tan[x]]*Sin[x]/2, {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Aug 26 2020 *)

Crossrefs

Cf. A009811.

Sequence in context: A099748 A023812 A062813 * A069717 A036679 A134490

Adjacent sequences: A024228 A024229 A024230 * A024232 A024233 A024234

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs Mar 1997

Previous Mathematica program replaced by Harvey P. Dale, Aug 26 2020

Status

approved