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 A302444 #18 Apr 09 2018 22:33:00
%S A302444 1,2,24,216,15936,-77056,90991744,-8523712768,2731708067840,
%T A302444 -684815907467264,268028469798256640,-114888252320482000896,
%U A302444 62022733722259702579200,-38635369828053720937463808,28349537098304682205749968896,-23874826868622028919177351004160
%N A302444 Expansion of e.g.f. arcsinh(x)/cos(x) (odd powers only).
%F A302444 a(n) = (2*n+1)! * [x^(2*n+1)] arcsinh(x)/cos(x).
%e A302444 arcsinh(x)/cos(x) = x/1! + 2*x^3/3! + 24*x^5/5! + 216*x^7/7! + 15936*x^9/9! - 77056*x^11/11! + ...
%t A302444 nmax = 16; Table[(CoefficientList[Series[ArcSinh[x]/Cos[x], {x, 0, 2 nmax + 1}], x] Range[0, 2 nmax + 1]!)[[n]], {n, 2, 2 nmax, 2}]
%Y A302444 Cf. A000182, A000364, A000795, A001818, A002084, A003701, A003702, A012821, A296742, A301942, A302542, A302543.
%K A302444 sign
%O A302444 0,2
%A A302444 _Ilya Gutkovskiy_, Apr 09 2018