A013048 - OEIS

%I #6 Aug 02 2018 19:53:36

%S 2,-13,545,-56943,11117105,-3487836823,1604931814265,

%T -1018249076690703,851905379176813025,-908738393030606172583,

%U 1203783991693440890209385,-1938726869386079701650506463

%N arctan(sinh(x)+tan(x))=2*x-13/3!*x^3+545/5!*x^5-56943/7!*x^7...

%t With[{nn=30},Take[CoefficientList[Series[ArcTan[Sinh[x]+Tan[x]],{x,0,nn}],x] Range[0,nn-1]!,{2,-1,2}]] (* _Harvey P. Dale_, Aug 02 2018 *)

%K sign

%O 0,1

%A Patrick Demichel (patrick.demichel(AT)hp.com)