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A183426
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Half the number of n X 3 0..2 arrays with no element equal its row sum plus its column sum mod 3.
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1
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9, 32, 256, 2097, 16384, 131072, 1048959, 8388608, 67108864, 536873985, 4294967296, 34359738368, 274877931519, 2199023255552, 17592186044416, 140737488551937, 1125899906842624, 9007199254740992, 72057594039500799
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 8*a(n-1) + 7*a(n-3) - 56*a(n-4) + 8*a(n-6) - 64*a(n-7).
Empirical g.f.: x*(9 - 40*x - 14*x^3 - 112*x^4 - 32*x^6) / ((1 + x)*(1 - 2*x)*(1 - 8*x)*(1 - x + x^2)*(1 + 2*x + 4*x^2)). - Colin Barker, Mar 29 2018
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EXAMPLE
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Some solutions for 4X3
..1..1..2....0..2..1....2..2..2....2..2..2....2..2..1....0..0..2....2..1..0
..1..0..1....1..0..0....1..0..0....0..1..1....1..2..1....1..2..0....2..1..1
..0..2..2....0..2..0....0..1..2....1..1..1....2..2..1....1..0..0....1..0..1
..2..2..1....1..0..2....1..0..0....0..2..2....2..2..1....0..1..2....1..0..2
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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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