A012742 - OEIS

%I #14 Oct 04 2025 23:17:30

%S 1,-3,53,-1799,154985,-16589771,3172731677,-721614303695,

%T 241340829836497,-94965599172723859,49224836859318783493,

%U -29702702631352493918103,22109389701103652762325561,-18928043482223039674124197467,19177016900409865735958434301165,-22074310371520428549856056403952735

%N Expansion of e.g.f. arctan(arctanh(x)*cos(x)) (odd powers only).

%e E.g.f. = x - 3/3!*x^3 + 53/5!*x^5 - 1799/7!*x^7 + ...

%t With[{nn=30},Take[CoefficientList[Series[ArcTan[ArcTanh[x]Cos[x]],{x,0,nn}],x] Range[0,nn-1]!,{2,-1,2}]] (* _Harvey P. Dale_, Nov 05 2015 *)

%K sign

%O 0,2

%A _Patrick Demichel_

%E Definition modified by _Harvey P. Dale_, Nov 05 2015

%E a(13)-a(15) from _Stefano Spezia_, Oct 04 2025