%I #8 Oct 04 2024 11:28:17

%S 1,-2,24,-664,28416,-942336,-260697984,165900454656,-85943912448000,

%T 48584004553543680,-31574321393019125760,23832746038658540666880,

%U -20858343927838973179822080,21048655959583804491297914880

%N sinh(arctan(arcsinh(x)))=x-2/3!*x^3+24/5!*x^5-664/7!*x^7+28416/9!*x^9...

%t With[{nn=30},Take[CoefficientList[Series[Sinh[ArcTan[ArcSinh[x]]],{x,0,nn}],x] Range[0,nn-1]!,{2,-1,2}]] (* _Harvey P. Dale_, Oct 04 2024 *)

%Y Bisection of A012213.

%K sign,changed

%O 0,2

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