%I #6 Nov 28 2016 19:50:54
%S 0,2,-16,80,14464,-1682432,76011520,26175092736,-10889734127616,
%T 1790915255599104,628448342217064448,-708415309969044275200,
%U 277815404352915818676224,89144743290434384702734336
%N arctan(tanh(x)*arctan(x))=2/2!*x^2-16/4!*x^4+80/6!*x^6+14464/8!*x^8...
%t With[{nn=30},Take[CoefficientList[Series[ArcTan[Tanh[x]*ArcTan[x]],{x,0,nn}],x] Range[0,nn]!,{1,-1,2}]] (* _Ray Chandler_, Nov 28 2016 *)
%K sign
%O 0,2
%A Patrick Demichel (patrick.demichel(AT)hp.com)
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