A009272 E.g.f. exp(tanh(x)*tan(x)), even powers only.

1, 2, 12, 232, 7952, 405152, 31111872, 3115956352, 414147567872, 68413355397632, 13936708915940352, 3412444856961083392, 987956358173680013312, 334650367409781717573632, 130572314003924554412900352, 58337032599905770133366013952

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Exp[Tanh[x]Tan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Feb 26 2012 *)

Crossrefs

Sequence in context: A156484 A333447 A347597 * A013141 A013143 A009359

Adjacent sequences: A009269 A009270 A009271 * A009273 A009274 A009275

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested Mar 15 1997 by Olivier Gérard.

More terms from Harvey P. Dale, Feb 26 2012

Status

approved