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Expansion of e.g.f.: exp(x)/cosh(tanh(x)).
1

%I #13 Feb 09 2014 04:05:00

%S 1,1,0,-2,8,56,-216,-2344,12032,168640,-1075328,-18467712,140944000,

%T 2863703168,-25464568832,-597301399296,6065774456832,161295676067840,

%U -1842040163078144,-54752864215838720,694620312112857088

%N Expansion of e.g.f.: exp(x)/cosh(tanh(x)).

%H Vincenzo Librandi, <a href="/A009298/b009298.txt">Table of n, a(n) for n = 0..200</a>

%t With[{nn=30},CoefficientList[Series[Exp[x]/Cosh[Tanh[x]],{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Jun 26 2013 *)

%K sign,easy

%O 0,4

%A _R. H. Hardin_

%E Extended with signs by _Olivier GĂ©rard_, Mar 15 1997

%E Definition clarified and prior Mathematica program replaced by _Harvey P. Dale_, Jun 26 2013