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A297735
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Number of 3Xn 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 2 or 4 neighboring 1s.
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1
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1, 3, 17, 34, 92, 223, 700, 1747, 4931, 12767, 35978, 94910, 262007, 698588, 1916541, 5144619, 14035991, 37816996, 102894248, 277866327, 754687018, 2040711739, 5537019209, 14984261865, 40631762944, 110008357730, 298195807995
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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) = 2*a(n-1) +4*a(n-2) -6*a(n-3) +7*a(n-4) -12*a(n-5) -19*a(n-6) +16*a(n-7) +10*a(n-8) +4*a(n-9)
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EXAMPLE
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Some solutions for n=7
..1..1..0..0..0..0..0. .0..0..1..1..1..1..1. .0..0..0..1..1..1..1
..0..1..1..0..1..1..0. .0..0..1..1..1..1..1. .1..1..0..1..1..1..1
..0..0..0..0..1..1..0. .0..0..0..0..0..0..0. .1..1..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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