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 A302585 #7 Jun 08 2019 08:28:58
%S A302585 1,1,3,18,165,2000,29855,527632,10762857,248811264,6428081979,
%T A302585 183537694208,5739195739277,195059957567488,7159662639822615,
%U A302585 282252719348582400,11894243092571825745,533554809104057434112,25384473065818477067123,1276688324194885747474432
%N A302585 a(n) = n! * [x^n] exp(n*x)/cosh(x).
%H A302585 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>
%F A302585 a(n) ~ n^n / cosh(1). - _Vaclav Kotesovec_, Jun 08 2019
%t A302585 Table[n! SeriesCoefficient[Exp[n x]/Cosh[x], {x, 0, n}], {n, 0, 19}]
%t A302585 Table[2^n EulerE[n, (n + 1)/2], {n, 0, 19}]
%Y A302585 Cf. A000364, A062024, A119880, A119881, A155585, A302583, A302584, A302586, A302587.
%K A302585 nonn
%O A302585 0,3
%A A302585 _Ilya Gutkovskiy_, Apr 10 2018