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A318077
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Number of nX3 0..1 arrays with every element unequal to 0, 1, 3 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
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1
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3, 4, 5, 11, 18, 32, 54, 98, 173, 315, 559, 1008, 1813, 3290, 5928, 10716, 19352, 35036, 63355, 114651, 207352, 375184, 678789, 1228507, 2222990, 4022469, 7278193, 13171060, 23835243, 43132890, 78050078, 141238045, 255588327, 462524188
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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) = a(n-1) +8*a(n-4) -2*a(n-5) -24*a(n-8) -3*a(n-9) +34*a(n-12) +4*a(n-13) -24*a(n-16) -a(n-17) +8*a(n-20) -a(n-24)
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EXAMPLE
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Some solutions for n=5
..0..0..0. .0..0..0. .0..0..1. .0..0..0. .0..0..1. .0..0..0. .0..1..1
..0..0..0. .0..0..0. .0..0..0. .0..1..0. .0..0..0. .0..0..1. .0..0..1
..0..0..0. .0..0..0. .0..0..0. .0..1..1. .0..0..0. .1..1..0. .0..0..0
..1..0..0. .0..0..0. .1..0..0. .1..0..0. .0..0..0. .0..1..0. .0..0..0
..1..1..0. .0..0..0. .1..1..0. .0..0..0. .1..0..0. .0..0..0. .0..0..0
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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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