A024262 - OEIS

%I #9 Apr 02 2017 15:31:49

%S 0,1,-4,-104,6656,-40064,-42409984,4996996096,379877605376,

%T -280033142964224,36077603872833536,18835361007974219776,

%U -11364456303888437346304,367251340814801013047296,3076185618615703435483283456,-1692496413849432696569477464064

%N Expansion of tanh(sin(x)^2)/2.

%t With[{nn=30},Take[CoefficientList[Series[Tanh[Sin[x]^2]/2,{x,0,nn}],x] Range[0,nn]!,{1,-1,2}]] (* _Harvey P. Dale_, Jun 03 2014 *)

%Y Cf. A009801.

%K sign

%O 0,3

%A _R. H. Hardin_

%E Extended with signs Mar 1997

%E More terms from and prior Mathematica program replaced by _Harvey P. Dale_, Jun 03 2014