%I #21 Sep 02 2019 02:04:47
%S 0,1,0,3,-4,45,-180,1743,-13704,135705,-1613160,18065883,-276222604,
%T 3655783365,-65652672540,1034667581223,-20865280018704,
%U 387014665823025,-8593188683674320,184059142857923763,-4464138375366282004,108277288526211374685,-2858191345505462554500
%N Expansion of e.g.f.: arctanh(exp(x)-sec(x)).
%e x + (3/3!)*x^3 - (4/4!)*x^4 + (45/5!)*x^5 - (180/6!)*x^6 + (1743/7!)*x^7 - ...
%t With[{nn=20},CoefficientList[Series[ArcTanh[Exp[x]-Sec[x]],{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Oct 11 2014 *)
%K sign
%O 0,4
%A Patrick Demichel (patrick.demichel(AT)hp.com)
%E Definition clarified and zero prepended by _Harvey P. Dale_, Oct 11 2014
%E Name edited by _Michel Marcus_, Sep 01 2019
%E More terms from _Petros Hadjicostas_, Sep 01 2019