This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A296467 #8 Dec 14 2017 03:44:28
%S A296467 1,0,8,112,8192,599808,80010240,13537247232,3160676007936,
%T A296467 929451393220608,343173318976733184,154043745649772986368,
%U A296467 82935056810462020632576,52660879605487383997317120,38970318170642827020431523840,33236188662933234332228627988480,32365907321554306913981616441262080
%N A296467 Expansion of e.g.f. arctan(arctanh(x)) (odd powers only).
%H A296467 Robert Israel, <a href="/A296467/b296467.txt">Table of n, a(n) for n = 0..224</a>
%F A296467 E.g.f.: arctanh(arctan(x)) (odd powers only, absolute values).
%F A296467 E.g.f.: i*(log(2 + i*log(1 - x) - i*log(1 + x)) - log(2 - i*log(1 - x) + i*log(1 + x)))/2, where i is the imaginary unit (odd powers only).
%e A296467 arctan(arctanh(x)) = x/1! + 8*x^5/5! + 112*x^7/7! + 8192*x^9/9! + 599808*x^11/11! + 80010240*x^13/13! + ...
%p A296467 S:= series(arctan(arctanh(x)),x,52):
%p A296467 seq(coeff(S,x,2*i+1)*(2*i+1)!,i=0..25); # _Robert Israel_, Dec 13 2017
%t A296467 nmax = 17; Table[(CoefficientList[Series[ArcTan[ArcTanh[x]], {x, 0, 2 nmax + 1}], x] Range[0, 2 nmax + 1]!)[[n]], {n, 2, 2 nmax, 2}]
%t A296467 nmax = 17; Table[(CoefficientList[Series[I (Log[2 + I Log[1 - x] - I Log[1 + x]] - Log[2 - I Log[1 - x] + I Log[1 + x]])/2, {x, 0, 2 nmax + 1}], x] Range[0, 2 nmax + 1]!)[[n]], {n, 2, 2 nmax, 2}]
%Y A296467 Cf. A003721, A010050, A012231, A296465.
%K A296467 nonn
%O A296467 0,3
%A A296467 _Ilya Gutkovskiy_, Dec 13 2017