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 A280100 #12 Dec 25 2016 23:11:37
%S A280100 1,32,12288,21233664,108716359680,1304596316160000,
%T A280100 31560794080542720000,1385645103312147578880000,
%U A280100 102160842176998016695664640000,11916040631525048667382323609600000,2097223151148408565459288955289600000000
%N A280100 a(n) = 4^(2*n) * (n!)^3 * (n+1)!.
%H A280100 Daniel Suteu, <a href="/A280100/b280100.txt">Table of n, a(n) for n = 0..50</a>
%F A280100 a(n) ~ Pi/4 * A134374(n).
%F A280100 a(n) ~ Pi^2 * 2^(4*n+2) / exp(4*n+1) * n^(3*n+3/2) * (n+1)^(n+3/2).
%F A280100 Lim_{n->infinity} a(n) / ((2n+1)!)^2 = Pi/4.
%F A280100 a(n) / ((2n+1)!)^2 = A278145(n) / A161736(n+2).
%o A280100 (PARI) a(n) = 4^(2*n) * (n!)^3 * (n+1)!;
%Y A280100 Cf. A134374, A161736, A278145.
%K A280100 nonn,easy
%O A280100 0,2
%A A280100 _Daniel Suteu_, Dec 25 2016