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A268889
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Number of 4Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two exactly once.
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1
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0, 71, 462, 4133, 27130, 186732, 1187838, 7529253, 46440962, 283673207, 1710265892, 10226321520, 60660804228, 357586190291, 2096177689750, 12229766790505, 71054027831574, 411303965509420, 2373090804832634
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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) +39*a(n-2) +14*a(n-3) -482*a(n-4) -1102*a(n-5) -111*a(n-6) +1758*a(n-7) +982*a(n-8) -1114*a(n-9) -743*a(n-10) +394*a(n-11) +206*a(n-12) -90*a(n-13) -17*a(n-14) +10*a(n-15) -a(n-16)
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EXAMPLE
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Some solutions for n=4
..0..0..0..0. .1..0..1..0. .1..0..0..1. .1..0..0..0. .0..1..0..1
..0..0..1..0. .0..0..0..0. .1..0..1..0. .1..0..1..0. .1..0..0..1
..0..0..1..0. .1..0..1..0. .1..0..0..1. .0..1..0..0. .0..1..0..0
..0..1..0..1. .0..1..0..1. .0..1..0..0. .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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