%I #11 Aug 01 2018 21:03:25
%S 0,1,0,-2,12,-32,72,152,-3808,48448,-333440,289408,26461952,
%T -393649024,4126861312,-34249082624,-93963415552,12871254335488,
%U -272828216803328,2591959365570560,6130847346393088
%N E.g.f.: log(sec(x)+arcsinh(x)) = x-2/3!*x^3+12/4!*x^4-32/5!*x^5+72/6!*x^6...
%t With[{nn=20},Rest[CoefficientList[Series[Log[Sec[x]+ArcSinh[x]],{x,0,nn}], x]Range[0,nn]!]] (* _Harvey P. Dale_, Jun 27 2012 *)
%K sign
%O 0,4
%A Patrick Demichel (patrick.demichel(AT)hp.com)
%E Definition clarified by _Harvey P. Dale_, Jun 27 2012
%E a(0)=0 inserted by _Sean A. Irvine_, Aug 01 2018