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 A322538 #18 Oct 19 2024 22:04:09
%S A322538 1,1,17,217,3281,50101,782153,12354469,197018321,3164588407,
%T A322538 51125645317,829858058019,13522838817929,221088393889403,
%U A322538 3624855419439957,59576725303913167,981272544393935569,16192709833199300337,267654541150392845543,4430755975190532983531
%N A322538 Number of arrays of n integers in -8..8 with sum zero.
%H A322538 Seiichi Manyama, <a href="/A322538/b322538.txt">Table of n, a(n) for n = 0..350</a>
%F A322538 a(n) = [x^(8*n)] (Sum_{k=0..16} x^k)^n.
%F A322538 a(n) ~ 17^n / (4*sqrt(3*Pi*n)). - _Vaclav Kotesovec_, Dec 15 2018
%p A322538 seq(add((-1)^k*binomial(n, k)*binomial(9*n-17*k-1, n-1), k = 0..floor(n/2)), n = 0..20); # _Peter Bala_, Oct 19 2024
%t A322538 a[n_] := If[n==0, 1, Coefficient[Expand[Sum[x^k, {k, 0, 16}]^n], x^(8n)]]; Array[a, 25, 0] (* _Amiram Eldar_, Dec 14 2018 *)
%o A322538 (PARI) {a(n) = polcoeff((sum(k=0, 16, x^k))^n, 8*n, x)}
%Y A322538 Column 8 of A201552.
%K A322538 nonn,easy
%O A322538 0,3
%A A322538 _Seiichi Manyama_, Dec 14 2018