A012135 - OEIS

%I #6 Mar 22 2019 17:15:07

%S 1,4,92,5272,567440,98979200,25530690624,9147312168576,

%T 4349983363258624,2652517304182955008,2018610268528861424640,

%U 1875904660571518053251072,2091013498538531655993561088

%N arcsin(arcsin(arctanh(x)))=x+4/3!*x^3+92/5!*x^5+5272/7!*x^7+567440/9!*x^9...

%t With[{nn=30},Take[CoefficientList[Series[ArcSin[ArcSin[ArcTanh[x]]],{x,0,nn}],x] Range[0,nn-1]!,{2,-1,2}]] (* _Harvey P. Dale_, Mar 22 2019 *)

%K nonn

%O 0,2

%A Patrick Demichel (patrick.demichel(AT)hp.com)