%I #20 Jul 22 2018 22:53:47

%S 1,-1,13,-373,18649,-1433129,156563045,-23043285021,4392102360241,

%T -1051530622359889,308633929353801661,-108880766753141666757,

%U 45418989883077539513225,-22097331609699052757909881

%N Expansion of E.g.f. cos(sin(tanh(x))), even powers only.

%H G. C. Greubel, <a href="/A009040/b009040.txt">Table of n, a(n) for n = 0..233</a>

%t With[{nn=30},Take[CoefficientList[Series[Cos[Sin[Tanh[x]]],{x,0,nn}],x] Range[0,nn]!,{1,-1,2}]] (* _Harvey P. Dale_, Jun 24 2013 *)

%o (PARI) x='x+O('x^60); v=Vec(serlaplace(cos(sin(tanh(x))))); vector(#v\2,n,v[2*n-1]) \\ _G. C. Greubel_, Jul 22 2018

%K sign

%O 0,3

%A _R. H. Hardin_

%E Extended with signs by _Olivier Gérard_, Mar 15 1997

%E Prior Mathematica program replaced by _Harvey P. Dale_, Jun 24 2013