%I #7 Nov 21 2013 12:46:01
%S 1,0,-12,120,-1008,-45120,-11491392,1378925184,-443544192768,
%T 53698137606144,-32840379055537152,7093049054642411520,
%U -6636093887068155801600,2065820944848385959936000
%N sech(arctan(x)*arcsin(x))=1-12/4!*x^4+120/6!*x^6-1008/8!*x^8...
%t With[{nn=30},Take[CoefficientList[Series[Sech[ArcTan[x]ArcSin[x]],{x,0,nn}], x]Range[0,nn]!,{1,-1,2}]] (* _Harvey P. Dale_, May 01 2012 *)
%K sign
%O 0,3
%A Patrick Demichel (patrick.demichel(AT)hp.com)