A009253 Expansion of exp(tan(x)/cos(x)).

1, 1, 1, 6, 21, 112, 717, 4592, 38857, 318208, 3158329, 32169984, 363525789, 4399544320, 56250039237, 779244812288, 11210469917713, 173483433263104, 2783865475754737, 47421793222656000, 840008000833503141

Offset: 0

Author

R. H. Hardin

Keywords

• nonn
• easy

Programs

Mathematica

With[{nn=30},CoefficientList[Series[Exp[Tan[x]/Cos[x]],{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Sep 30 2012 *)

Extensions

Extended and signs tested Mar 15 1997 by Olivier Gérard.