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 A367392 #11 Nov 24 2023 08:29:38
%S A367392 0,1,30,1806,186480,29607600,6711344640,2060056318320,823172919528960,
%T A367392 415357755774998400,258323865658578720000,194165346649139268480000,
%U A367392 173524374976148227519488000,181871966450361851863879680000,220951172052769326900328396800000
%N A367392 a(n) = Sum_{k=0..n} (-1)^k * binomial(n, k) * (n - k)^(2*n + 1).
%F A367392 a(n) = n! * Stirling2(2*n + 1, n) = A000142(n) * A247238(n).
%p A367392 a := n -> n! * Stirling2(2*n + 1, n):
%p A367392 seq(a(n), n = 0..14);
%t A367392 A367392[n_]:=n!StirlingS2[2n+1,n];
%t A367392 Array[A367392,20,0] (* _Paolo Xausa_, Nov 24 2023 *)
%Y A367392 Cf. A000142, A048993, A131689, A247238.
%K A367392 nonn
%O A367392 0,3
%A A367392 _Peter Luschny_, Nov 21 2023