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 A294321 #5 Oct 28 2017 11:05:00
%S A294321 2,1440,5225472000,455547719673446400000,
%T A294321 2916586742141623158009180979200000000,
%U A294321 3278245620793706216637861108629164518335840256000000000000
%N A294321 a(n) = Product_{k=0..n} (4*k + 2)!.
%F A294321 a(n) ~ 2^(4*n^2 + 19*n/2 + 35/6) * n^(2*n^2 + 9*n/2 + 113/48) * Pi^(n/2 + 3/4) / (A^(1/4) * Gamma(1/4)^(1/2) * exp(3*n^2 + 9*n/2 - 1/48)), where A is the Glaisher-Kinkelin constant A074962.
%F A294321 A268505(n) * A294320(n) * A294321(n) * A294322(n) = A000178(4*n + 3).
%t A294321 Table[Product[(4*k + 2)!, {k, 0, n}] , {n, 0, 10}]
%Y A294321 Cf. A268505, A294319, A294320, A294322, A294324.
%K A294321 nonn
%O A294321 0,1
%A A294321 _Vaclav Kotesovec_, Oct 28 2017