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%I #14 Dec 15 2018 06:28:04
%S 1,1,17,217,3281,50101,782153,12354469,197018321,3164588407,
%T 51125645317,829858058019,13522838817929,221088393889403,
%U 3624855419439957,59576725303913167,981272544393935569,16192709833199300337,267654541150392845543,4430755975190532983531
%N Number of arrays of n integers in -8..8 with sum zero.
%H Seiichi Manyama, <a href="/A322538/b322538.txt">Table of n, a(n) for n = 0..350</a>
%F a(n) = [x^(8*n)] (Sum_{k=0..16} x^k)^n.
%F a(n) ~ 17^n / (4*sqrt(3*Pi*n)). - _Vaclav Kotesovec_, Dec 15 2018
%t 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 (PARI) {a(n) = polcoeff((sum(k=0, 16, x^k))^n, 8*n, x)}
%Y Column 8 of A201552.
%K nonn
%O 0,3
%A _Seiichi Manyama_, Dec 14 2018
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