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 A302606 #18 Oct 25 2024 10:14:39
%S A302606 0,1,4,26,240,2884,42660,748544,15185856,349574544,9000902500,
%T A302606 256293989984,7996078704240,271246034903232,9939835626507332,
%U A302606 391303051339622400,16469438021801262848,737992773619777599744,35077254665501330210628,1762671472887447792620032
%N A302606 a(n) = n! * [x^n] exp(n*x)*arcsinh(x).
%H A302606 N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>
%F A302606 a(n) ~ arcsinh(1) * n^n = log(1 + sqrt(2)) * n^n. - _Vaclav Kotesovec_, Jun 09 2019
%F A302606 a(n) = Sum_{k=1..n, k odd} (-1)^((k-1)/2)*binomial(n,k)*(k-2)!!^2*n^(n-k). - _Fabian Pereyra_, Oct 05 2024
%t A302606 Table[n! SeriesCoefficient[Exp[n x] ArcSinh[x], {x, 0, n}], {n, 0, 19}]
%Y A302606 Cf. A001818, A002866, A291483, A302583, A302584, A302585, A302586, A302587, A302605, A302608, A302609.
%K A302606 nonn
%O A302606 0,3
%A A302606 _Ilya Gutkovskiy_, Apr 10 2018