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 A376321 #10 Sep 20 2024 16:06:14 %S A376321 2,9,144,5929,466560,59213025,10958689280,2771535732849, %T A376321 915539439919104,382088350057032025,196357891384811520000, %U A376321 121752085389995771825625,89582478947424173216497664,77138638421388109999960896369,76829768389915556918132736000000 %N A376321 Obverse convolution (n^2 + 1)**(n^2 + 1); see Comments. %C A376321 See A374848 for the definition of obverse convolution and a guide to related sequences. %C A376321 a(2k+1) is a square for k>=0. %F A376321 a(n) ~ n^(2*n+2) / exp(2*n - Pi*n/2). - _Vaclav Kotesovec_, Sep 20 2024 %t A376321 s[n_] := n^2 + 1; t[n_] := n^2 + 1; %t A376321 u[n_] := Product[s[k] + t[n - k], {k, 0, n}]; %t A376321 Table[u[n], {n, 0, 20}] %Y A376321 Cf. A323540, A374848, A375051. %K A376321 nonn %O A376321 0,1 %A A376321 _Clark Kimberling_, Sep 20 2024