A009241 Expansion of e.g.f.: exp(tan(tanh(x))).

1, 1, 1, 1, 1, -7, -47, -55, 449, 2897, 18209, 5105, -1441087, -7252983, 41192817, 341550201, 2660018305, 43255573537, -460752070079, -11238852308639, 21450325749889, 963068748879257, 1057483104728337, 153386988236833449

Offset: 0

Author

R. H. Hardin

Keywords

• sign
• easy

Programs

Mathematica

With[{nn=30},CoefficientList[Series[Exp[Tan[Tanh[x]]],{x,0,nn}],x] Range[ 0,nn]!] (* Harvey P. Dale, Apr 05 2022 *)

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Definition clarified and prior Mathematica program replaced by Harvey P. Dale, Apr 05 2022