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A322537
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Number of arrays of 10 integers in -n..n with sum zero.
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2
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1, 8953, 856945, 17538157, 167729959, 1018872811, 4577127763, 16581420835, 51125645317, 139071924069, 342237634221, 775938666273, 1643151128475, 3284313415527, 6247630238079, 11385659856231, 19984965376233, 33936690554865, 55957080110537, 89868204063989, 140950465124591
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) = [x^(10*n)] (Sum_{k=0..2*n} x^k)^10.
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MATHEMATICA
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a[n_] := Coefficient[Expand[Sum[x^k, {k, 0, 2n}]^10, x], x, 10n]; Array[a, 25, 0] (* Amiram Eldar, Dec 14 2018 *)
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PROG
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(PARI) {a(n) = polcoeff((sum(k=0, 2*n, x^k))^10, 10*n, x)}
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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