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 A328808 #11 Oct 28 2019 05:31:50
%S A328808 1,3,23,225,2583,32133,422069,5757699,80790775,1158593589,16905540753,
%T A328808 250185539079,3746205581589,56652844671855,864032059578879,
%U A328808 13274539401672345,205252378269637815,3191578469685269925,49876569284504593505,782943268394316187815
%N A328808 Constant term in the expansion of (3 + x + y + z + 1/x + 1/y + 1/z + x*y + y*z + z*x + 1/(x*y) + 1/(y*z) + 1/(z*x) + x*y*z + 1/(x*y*z))^n.
%F A328808 a(n) = Sum_{i=0..n} binomial(n,i)*Sum_{j=0..i} binomial(i,j)^4.
%F A328808 From _Vaclav Kotesovec_, Oct 28 2019: (Start)
%F A328808 Recurrence: n^3*a(n) = (2*n - 1)*(8*n^2 - 8*n + 3)*a(n-1) + (n-1)*(22*n^2 - 44*n + 13)*a(n-2) - 44*(n-2)*(n-1)*(2*n - 3)*a(n-3) + 51*(n-3)*(n-2)*(n-1)*a(n-4).
%F A328808 a(n) ~ sqrt(2) * 17^(n + 3/2) / (64 * Pi^(3/2) * n^(3/2)). (End)
%t A328808 Table[Sum[Binomial[n, i]*Sum[Binomial[i, j]^4, {j, 0, i}], {i, 0, n}], {n, 0, 20}] (* _Vaclav Kotesovec_, Oct 28 2019 *)
%o A328808 (PARI) {a(n) = polcoef(polcoef(polcoef((1+(1+x)*(1+y)*(1+z)+(1+1/x)*(1+1/y)*(1+1/z))^n, 0), 0), 0)}
%o A328808 (PARI) {a(n) = sum(i=0, n, binomial(n, i)*sum(j=0, i, binomial(i, j)^4))}
%Y A328808 Column k=4 of A328807.
%Y A328808 Cf. A005260, A328725, A328735.
%K A328808 nonn
%O A328808 0,2
%A A328808 _Seiichi Manyama_, Oct 28 2019