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 A384027 #9 May 17 2025 14:01:39
%S A384027 1,0,0,0,1296,2764800,8041766400,34726710251520,219045033712578816,
%T A384027 1956771788423009992704,24009126017002632247173120,
%U A384027 393692515265172002272138690560,8424620140673205407840209386541056,230472036551670538296109810120063451136,7917891968134805796965854747528387122954240
%N A384027 a(n) = [x^(3*n)] Product_{k=0..n-1} (1 + k*x)^4.
%F A384027 a(n) = Sum_{i, j, k, l>=0 and i+j+k+l=n} |Stirling1(n,i) * Stirling1(n,j) * Stirling1(n,k) * Stirling1(n,l)|.
%o A384027 (PARI) a(n) = sum(i=0, n, sum(j=0, n-i, sum(k=0, n-i-j, abs(stirling(n, i, 1)*stirling(n, j, 1)*stirling(n, k, 1)*stirling(n, n-i-j-k, 1)))));
%Y A384027 Cf. A342111, A384026.
%Y A384027 Cf. A384029, A384030.
%K A384027 nonn
%O A384027 0,5
%A A384027 _Seiichi Manyama_, May 17 2025