%I #13 Apr 02 2017 14:41:53
%S 0,1,-2,99,-2020,158437,-9588134,1187244807,-141412522312,
%T 26139574347337,-5065084577305802,1323760751709283371,
%U -375086579956164869164,132463397392835073766957,-51304161208549419113557358
%N E.g.f. tan(x)*sin(tanh(x))/2 (even powers only).
%e tan(x)*sin(tanh(x))/2 = x^2 - 2*x^4 + 99*x^6 - 2020*x^8 + 158437*x^10 -+ ...
%t With[{nn=30},Take[CoefficientList[Series[Tan[x]Sin[Tanh[x]]/2,{x,0,nn}],x]Range[0,nn]!,{1,-1,2}]] (* _Harvey P. Dale_, Jan 12 2013 *)
%Y Cf. A009743.
%K sign
%O 0,3
%A _R. H. Hardin_
%E Extended with signs Mar 1997