A009272 Expansion of 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

Author

R. H. Hardin

Keywords

• nonn
• changed

Programs

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 *)

Extensions

Extended and signs tested by Olivier Gérard, Mar 15 1997

More terms from Harvey P. Dale, Feb 26 2012