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A268785
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Number of nX4 binary arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.
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1
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5, 48, 302, 1714, 9085, 46195, 228384, 1105510, 5267662, 24786180, 115455033, 533317129, 2446323573, 11154503019, 50600348892, 228514035985, 1027932765869, 4607917805325, 20591918472965, 91765529043193, 407916504889146
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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) = 2*a(n-1) +19*a(n-2) +10*a(n-3) -122*a(n-4) -320*a(n-5) -295*a(n-6) +8*a(n-7) +176*a(n-8) +20*a(n-9) -98*a(n-10) -6*a(n-11) +43*a(n-12) -6*a(n-13) -11*a(n-14) +6*a(n-15) -a(n-16)
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EXAMPLE
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Some solutions for n=4
..0..0..1..0. .0..0..0..1. .1..0..0..1. .1..0..0..0. .0..1..0..0
..0..0..0..0. .0..0..0..0. .0..0..0..0. .0..1..0..1. .0..0..0..1
..1..0..0..0. .0..0..0..1. .1..0..0..1. .1..0..0..0. .0..1..0..0
..1..0..0..0. .1..1..0..0. .0..0..0..1. .0..1..0..0. .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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