A012678 - OEIS

%I #4 Feb 24 2012 12:51:04

%S 2,-16,440,-25856,2702368,-442400000,104680527744,-33826438987776,

%T 14318658795815424,-7689929339111084032,5108988246588765059072,

%U -4113772753950316528205824,3947181962951541949825294336

%N arcsin(tanh(x)*arctan(x))=2/2!*x^2-16/4!*x^4+440/6!*x^6-25856/8!*x^8...

%K sign

%O 0,1

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