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 A371548 #7 Mar 30 2024 02:33:16
%S A371548 1,2,2,16,44,248,2136,13536,116448,1075392,13066560,136385280,
%T A371548 1811975040,23777683200,354509003520,5632664970240,93712140103680,
%U A371548 1631567291719680,30968760551178240,605247894280028160,12515132360676556800,274444506310599475200
%N A371548 Expansion of e.g.f. Product_{k>=1} (1 + 2*x^k/k).
%F A371548 a(n) ~ n! * n / (2*exp(2*gamma)), where gamma is the Euler-Mascheroni constant A001620. - _Vaclav Kotesovec_, Mar 28 2024
%t A371548 nmax = 21; CoefficientList[Series[Product[(1 + 2 x^k/k), {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!
%Y A371548 Cf. A007838, A032297, A371547.
%K A371548 nonn
%O A371548 0,2
%A A371548 _Ilya Gutkovskiy_, Mar 27 2024