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 A302579 #4 Apr 10 2018 14:17:11
%S A302579 1,2,24,632,28784,1991552,193410624,24993180032,4134783110144,
%T A302579 850499728758272,212579274719007744,63381008507902595072,
%U A302579 22200896917210834817024,9019985888570141052280832,4204783981520054371872374784,2228007853953954434037178007552
%N A302579 Expansion of e.g.f. exp(cosh(x)/cos(x)-1) (even powers only).
%H A302579 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>
%F A302579 a(n) = (2*n)! * [x^(2*n)] exp(cosh(x)/cos(x)-1).
%e A302579 exp(cosh(x)/cos(x)-1) = 1 + 2*x^2/2! + 24*x^4/4! + 632*x^6/6! + 28784*x^8/8! + ...
%t A302579 nmax = 15; Table[(CoefficientList[Series[Exp[Cosh[x]/Cos[x] - 1], {x, 0, 2 nmax}], x] Range[0, 2 nmax]!)[[n]], {n, 1, 2 nmax + 1, 2}]
%Y A302579 Cf. A000795, A005046, A006229, A009234, A009253, A009254, A009274, A012853, A217502.
%K A302579 nonn
%O A302579 0,2
%A A302579 _Ilya Gutkovskiy_, Apr 10 2018