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A304422
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Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4 or 5 king-move adjacent elements, with upper left element zero.
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1
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1, 25, 124, 836, 5227, 33263, 210954, 1338995, 8497693, 53931843, 342283175, 2172337312, 13786969248, 87500479337, 555331175880, 3524468904668, 22368420155320, 141963579269696, 900987092575923, 5718211285108957
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OFFSET
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1,2
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 4*a(n-1) +15*a(n-2) +7*a(n-3) -36*a(n-4) -72*a(n-5) -51*a(n-6) -29*a(n-7) -19*a(n-8) -4*a(n-9) for n>10
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EXAMPLE
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Some solutions for n=5
..0..0..1. .0..1..1. .0..1..1. .0..1..1. .0..1..0. .0..0..0. .0..1..1
..1..0..1. .0..0..0. .1..0..0. .1..0..0. .0..0..0. .1..0..1. .1..0..0
..1..0..0. .0..0..0. .1..1..0. .0..0..1. .1..0..1. .0..1..0. .1..0..0
..1..1..0. .1..0..1. .1..0..0. .0..1..0. .1..0..1. .1..1..1. .1..0..1
..1..0..0. .0..1..0. .0..1..1. .1..1..0. .0..1..0. .0..0..0. .0..1..1
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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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