A009265 Expansion of exp(tanh(x))/cosh(x).

1, 1, 0, -4, -8, 32, 216, -264, -7552, -9216, 349568, 1548032, -20281216, -190744448, 1350879232, 25395878400, -84211707904, -3862395551744, -286327484416, 674521189158912, 2529465981566976, -133945803441307648

Offset

0,4

Links

Table of n, a(n) for n=0..21.

Mathematica

With[{nn=30}, CoefficientList[Series[Exp[Tanh[x]]/Cosh[x], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Nov 13 2014 *)

Crossrefs

Sequence in context: A222537 A208924 A032467 * A173326 A173652 A149095

Adjacent sequences: A009262 A009263 A009264 * A009266 A009267 A009268

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program replaced by Harvey P. Dale, Nov 13 2014

Status

approved