Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #6 Feb 17 2023 15:57:34
%S 1,1,5,-499,-12055,-2156871,-24423763,-27205910523,2396435716433,
%T -1214149548475407,375616253471952085,-173184506373765285763,
%U 93896424495536603892025,-57465007424690895944339543
%N sin(sec(x)*arcsinh(x))=x+1/3!*x^3+5/5!*x^5-499/7!*x^7-12055/9!*x^9...
%t With[{nn=30},Take[CoefficientList[Series[Sin[Sec[x]ArcSinh[x]],{x,0,nn}],x] Range[0,nn-1]!,{2,-1,2}]] (* _Harvey P. Dale_, Feb 17 2023 *)
%K sign
%O 0,3
%A Patrick Demichel (patrick.demichel(AT)hp.com)