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A283728
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Number of 3Xn 0..1 arrays with no 1 equal to more than two of its horizontal, diagonal and antidiagonal neighbors, with the exception of exactly one element.
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1
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0, 6, 159, 1088, 7839, 56106, 369328, 2391828, 15258307, 95588636, 592291968, 3636441278, 22144892123, 133969251618, 805895076555, 4824002960360, 28752431241931, 170726461743312, 1010344566340239, 5961242307456936
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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) = 10*a(n-1) -19*a(n-2) -303*a(n-4) +588*a(n-5) +507*a(n-6) +2028*a(n-7) -5758*a(n-8) -5310*a(n-9) +4331*a(n-10) +15486*a(n-11) +7169*a(n-12) -26070*a(n-13) -7596*a(n-14) +7938*a(n-15) +16823*a(n-16) -5350*a(n-17) -11837*a(n-18) +11864*a(n-19) -5720*a(n-20) +1400*a(n-21) -196*a(n-22)
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EXAMPLE
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Some solutions for n=4
..1..1..1..1. .1..0..1..0. .1..0..0..1. .0..1..0..1. .0..0..0..0
..0..0..0..1. .1..1..1..1. .0..0..1..1. .0..1..1..0. .1..0..1..0
..1..0..0..1. .1..0..0..0. .0..1..1..0. .1..0..0..0. .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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