A009526 Expansion of sin(tanh(x))/cos(x).

1, 0, 32, -280, 27520, -1072896, 137702528, -12544190464, 2268209053696, -366953307820032, 91839717688770560, -22828783486234329088, 7664698989016298979328, -2683708217718933773352960

Offset

0,3

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sin[Tanh[x]]/Cos[x], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Nov 30 2014 *)

Crossrefs

Sequence in context: A248884 A223904 A122103 * A304345 A316216 A305640

Adjacent sequences: A009523 A009524 A009525 * A009527 A009528 A009529

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program replaced by Harvey P. Dale, Nov 30 2014

Status

approved