A009254 - OEIS

%I #13 Mar 07 2018 19:19:21

%S 1,1,1,0,-3,12,117,336,-903,-2096,111529,1043328,687093,-29488704,

%T 320199453,8894706432,44530596081,-389860902656,254346923089,

%U 170568226222080,2006766293627373,-6327905330549760,-141849542553657147

%N Expansion of exp(tan(x)/cosh(x)).

%t With[{nn=30},CoefficientList[Series[Exp[Tan[x]/Cosh[x]],{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Mar 07 2018 *)

%K sign,easy

%O 0,5

%A _R. H. Hardin_

%E Extended with signs by _Olivier Gérard_, Mar 15 1997

%E Previous Mathematica program replaced by _Harvey P. Dale_, Mar 07 2018