%I #6 Nov 28 2016 18:36:41
%S 0,2,-12,-50,12936,-643142,-60323780,22895524678,-2421315237488,
%T -864760878344718,527455288321939204,-55917569000158790850,
%U -108932420480580224669416,83957330220575698201816746
%N arctan(arctan(x)*sin(x))=2/2!*x^2-12/4!*x^4-50/6!*x^6+12936/8!*x^8...
%t With[{nn=30},Take[CoefficientList[Series[ArcTan[ArcTan[x]*Sin[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)