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A301903
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Number of nX5 0..1 arrays with every element equal to 0, 2 or 3 horizontally or antidiagonally adjacent elements, with upper left element zero.
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1
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1, 3, 2, 8, 12, 64, 196, 864, 3236, 13280, 52260, 210400, 838180, 3358176, 13419044, 53698016, 214737444, 859037152, 3435930148, 13744070112, 54975406628, 219903024608, 879608603172, 3518440005088, 14073746039332, 56295006526944
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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) +5*a(n-2) -20*a(n-3) -4*a(n-4) +16*a(n-5) for n>6
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EXAMPLE
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Some solutions for n=5
..0..1..1..1..1. .0..1..1..0..0. .0..1..0..1..0. .0..1..1..0..0
..1..1..0..1..1. .1..1..0..0..0. .0..1..0..1..0. .1..1..0..0..1
..1..1..0..1..1. .0..1..1..0..1. .0..1..0..1..0. .0..1..0..0..0
..1..1..0..1..1. .1..1..0..0..0. .0..1..0..1..0. .0..1..1..0..0
..1..1..1..1..0. .0..1..0..0..1. .0..1..0..1..0. .1..1..0..0..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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