A012242 - OEIS

%I #6 May 27 2014 11:08:04

%S -1,6,-72,1456,-47104,2390784,-180612096,18625189888,-2431403622400,

%T 384624656646144,-72343735465672704,16067422146130345984,

%U -4193787904779561730048,1276366494840535652499456

%N log(cos(tanh(x)))=-1/2!*x^2+6/4!*x^4-72/6!*x^6+1456/8!*x^8...

%t With[{nn=30},Take[CoefficientList[Series[Log[Cos[Tanh[x]]],{x,0,nn}],x] Range[0,nn]!,{3,-1,2}]] (* _Harvey P. Dale_, May 27 2014 *)

%K sign

%O 0,2

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