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 A384043 #5 May 18 2025 04:10:05
%S A384043 1,2,50,4188,735600,221302710,101667388082,66218673102680,
%T A384043 58048466179356672,65901249246347377770,94061755750395244537250,
%U A384043 164863945136411230998746612,348110204753572939058548570000,871547135491620353615820806025918,2552918049709989779004770502542335650
%N A384043 a(n) = [x^n] Product_{k=1..n} (1 + k^2*x) / (1 - k^2*x).
%F A384043 a(n) ~ c * d^n * n!^2 / n^(3/2), where d = 16.6871576653578743696262746377576281620174969944584774545888... and c = 0.1371163625236187865398447973928851799479072107076663329994...
%t A384043 Table[SeriesCoefficient[Product[(1+k^2*x)/(1-k^2*x), {k, 1, n}], {x, 0, n}], {n, 0, 15}]
%Y A384043 Cf. A001044, A298851.
%Y A384043 Cf. A350366, A384044, A351764.
%K A384043 nonn
%O A384043 0,2
%A A384043 _Vaclav Kotesovec_, May 18 2025