%I #15 Sep 08 2022 08:44:38
%S 0,1,0,-1,-4,-3,60,107,-264,-11175,-40200,142903,2392436,8175637,
%T -327277132,-3256146845,-19824913424,184016913969,1628105059824,
%U -33266797736465,-1067099983418644,-14633634217342547,-39212918007355092,458935991667836379
%N Expansion of e.g.f. tanh(exp(x) - sec(x)).
%H Vincenzo Librandi, <a href="/A013335/b013335.txt">Table of n, a(n) for n = 0..200</a>
%e x - 1/3!*x^3 - 4/4!*x^4 - 3/5!*x^5 + 60/6!*x^6 ...
%t Range[0, 30]! CoefficientList[Series[Tanh[Exp[x] - Sec[x]], {x, 0, 30}], x] (* _Vincenzo Librandi_, Aug 06 2018 *)
%o (Magma) m:=30; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(1+Tanh(Exp(x) - Sec(x)))); [0] cat [Factorial(n-1)*b[n]: n in [2..m]];// _Vincenzo Librandi_, Aug 06 2018
%o (PARI) x = 'x + O('x^30); concat(0, Vec(serlaplace(tanh(exp(x) - 1/cos(x))))) \\ _Michel Marcus_, Aug 06 2018
%K sign
%O 0,5
%A Patrick Demichel (patrick.demichel(AT)hp.com)
%E a(0)=0 inserted and title improved by _Sean A. Irvine_, Aug 05 2018