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 A280845 #7 Apr 11 2023 13:26:34
%S A280845 0,16,8192,15925248,86973087744,1087163596800000,27052109211893760000,
%T A280845 1212439465398129131520000,90809637490664903729479680000,
%U A280845 10724436568372543800644091248640000,1906566501044007786781171777536000000000,491287106495421596910231193510320537600000000
%N A280845 a(n) = 16^n * n * (n!)^4.
%H A280845 Daniel Suteu, <a href="/A280845/b280845.txt">Table of n, a(n) for n = 0..50</a>
%F A280845 a(n) ~ Pi/4 * A134374(n).
%F A280845 a(n) ~ Pi^2 * 4^(2n + 1) / exp(4n) * n^(4n + 3).
%F A280845 Lim_{n->infinity} a(n) / ((2n+1)!)^2 = Pi/4.
%t A280845 Table[16^n*n*(n!)^4, {n, 0, 12}] (* _Wesley Ivan Hurt_, Apr 11 2023 *)
%o A280845 (PARI) a(n) = 16^n * n * (n!)^4;
%Y A280845 Cf. A134374, A280100.
%K A280845 nonn,easy
%O A280845 0,2
%A A280845 _Daniel Suteu_, Jan 09 2017