A013487 - OEIS

%I #6 Nov 30 2014 11:33:35

%S 1,0,0,0,-560,50400,-4403520,451651200,-55603258880,8098495142400,

%T -1364657183216640,258905686980864000,-53203592135631564800,

%U 11000355030582368256000,-1812425415209721012879360

%N cos(cos(x)-sech(x))=1-560/8!*x^8+50400/10!*x^10-4403520/12!*x^12...

%t With[{nn=30},Take[CoefficientList[Series[Cos[Cos[x]-Sech[x]],{x,0,nn}],x] Range[0,nn]!,{1,-1,2}]] (* _Harvey P. Dale_, Nov 30 2014 *)

%K sign

%O 0,5

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