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A297757
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Number of nX3 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2, 3 or 4 neighboring 1s.
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1
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1, 12, 52, 186, 1045, 5685, 28565, 148681, 783104, 4082179, 21289432, 111293510, 581390557, 3036127779, 15859365566, 82842802213, 432710054944, 2260195540670, 11805906967573, 61666590418664, 322107101630217, 1682485627292574
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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) = 3*a(n-1) +2*a(n-2) +52*a(n-3) +2*a(n-4) +27*a(n-5) -378*a(n-6) -365*a(n-7) -173*a(n-8) +386*a(n-9) +1006*a(n-10) +488*a(n-11) +468*a(n-12) +328*a(n-13) -120*a(n-14) -80*a(n-15)
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EXAMPLE
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Some solutions for n=7
..1..1..0. .0..1..1. .0..1..1. .1..1..0. .0..1..0. .0..1..1. .1..1..1
..1..1..1. .1..1..0. .1..1..0. .1..1..0. .1..1..1. .0..1..1. .0..1..0
..0..1..0. .1..1..0. .0..1..1. .0..1..1. .0..1..0. .0..1..1. .0..1..0
..0..0..0. .0..1..0. .0..1..1. .0..0..0. .1..1..1. .0..0..0. .1..0..1
..0..1..0. .1..1..0. .0..1..0. .0..1..0. .0..1..0. .0..1..0. .1..1..0
..1..1..1. .1..1..1. .0..1..1. .1..1..1. .1..1..1. .1..1..1. .0..1..1
..0..1..0. .0..0..0. .1..1..1. .0..0..0. .1..1..1. .1..1..0. .1..1..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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