A009517 - OEIS

%I #18 Apr 01 2017 22:32:53

%S 1,-2,32,-688,29952,-1922560,160364544,-19815696384,2743045259264,

%T -538516252917760,112957538226929664,-31810392390007521280,

%U 9466977656209217159168,-3592556624975295837896704

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

%t With[{nn=30},Take[CoefficientList[Series[Sin[Tan[x]/Cosh[x]],{x,0,nn}], x]Range[0,nn-1]!,{2,-1,2}]] (* _Harvey P. Dale_, May 08 2012 *)

%K sign

%O 1,2

%A _R. H. Hardin_

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