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A201550
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Number of arrays of n integers in -6..6 with sum zero.
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7
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1, 1, 13, 127, 1469, 17151, 204763, 2473325, 30162301, 370487485, 4577127763, 56813989827, 707972099627, 8851373201919, 110976634957761, 1394804756117877, 17567994350713469, 221690794842728445, 2802194053806820153
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OFFSET
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0,3
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COMMENTS
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LINKS
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FORMULA
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EXAMPLE
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Some solutions for n=5
.-2...-5...-2...-1....3...-6....0...-3....1....6...-6...-2....5....0...-4...-3
..2...-3...-2....3....0...-1....6...-4....6....1....5....2...-1....3....2....3
..0...-4....4...-6...-4....1...-3....0...-4...-5....0...-6...-3....0....4...-4
..0....6....3....5...-5....6....0....4....3...-4....4....0...-5...-3....3...-1
..0....6...-3...-1....6....0...-3....3...-6....2...-3....6....4....0...-5....5
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MATHEMATICA
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Table[Coefficient[Expand[Sum[x^j, {j, 0, 12}]^n], x^(6*n)], {n, 1, 20}] (* Vaclav Kotesovec, Aug 09 2013 *)
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PROG
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(PARI) {a(n) = polcoeff((sum(k=0, 12, x^k))^n, 6*n, x)} \\ Seiichi Manyama, Dec 14 2018
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CROSSREFS
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Cf. A001405, A002426, A005190, A005191, A018901, A025012, A025013, A025014, A025015, A201549, A225779.
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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