A009688 - OEIS

%I #11 Mar 20 2023 09:21:14

%S 1,6,132,6888,631120,88901472,17815778112,4813349520000,

%T 1685527674636544,742370072201602560,401601528167832511488,

%U 261760691714482869528576,202316143535276408972627968

%N Expansion of tan(sinh(x)/cos(x)).

%t With[{nn=30},Take[CoefficientList[Series[Tan[Sinh[x]/Cos[x]],{x,0,nn}],x] Range[ 0,nn-1]!,{2,-1,2}]] (* _Harvey P. Dale_, Mar 20 2023 *)

%K nonn

%O 0,2

%A _R. H. Hardin_

%E Extended and signs tested Mar 15 1997 by _Olivier Gérard_.

%E Previous Mathematica program replaced by _Harvey P. Dale_, Mar 20 2023