A012557 - OEIS

%I #6 Mar 01 2015 10:18:44

%S 2,-4,350,-11240,1461658,-167279660,35689423926,-8594866078032,

%T 2902777731046578,-1163594305273709524,584328120817240344206,

%U -346295976826690961613880,244030359200524004600252746

%N tan(sinh(x)*arctan(x))=2/2!*x^2-4/4!*x^4+350/6!*x^6-11240/8!*x^8...

%t With[{nn=30},Take[CoefficientList[Series[Tan[Sinh[x]ArcTan[x]],{x,0,nn}],x] Range[0,nn]!,{3,-1,2}]] (* _Harvey P. Dale_, Mar 01 2015 *)

%K sign

%O 0,1

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