

A322535


Number of arrays of 8 integers in n..n with sum zero.


2



1, 1107, 38165, 398567, 2306025, 9377467, 30162301, 82073295, 197018321, 429042211, 864287973, 1633586615, 2927984825, 5017519755, 8273550157, 13194953119, 20438495649, 30853690355, 45522444469, 65803811463, 93384154505, 130333031003, 179165107485, 242908414063
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OFFSET

0,2


LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..10000


FORMULA

a(n) = [x^(8*n)] (Sum_{k=0..2*n} x^k)^8.
a(n) = (2*n+1)*(9664*n^6+28992*n^5+37360*n^4+26400*n^3+10936*n^2+2568*n+315)/315.


MATHEMATICA

a[n_] := Coefficient[Expand[Sum[x^k, {k, 0, 2n}]^8, x], x, 8n]; Array[a, 25, 0] (* Amiram Eldar, Dec 14 2018 *)


PROG

(PARI) {a(n) = polcoeff((sum(k=0, 2*n, x^k))^8, 8*n, x)}


CROSSREFS

Row 8 of A201552.
Sequence in context: A295991 A157376 A185501 * A184370 A172638 A278633
Adjacent sequences: A322532 A322533 A322534 * A322536 A322537 A322538


KEYWORD

nonn


AUTHOR

Seiichi Manyama, Dec 14 2018


STATUS

approved



