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A207854
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Number of nX4 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 0 and 1 0 1 vertically
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3
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9, 81, 289, 1369, 5929, 26569, 117649, 522729, 2319529, 10297681, 45711121, 202920025, 900780169, 3998665225, 17750499361, 78796419849, 349785896329, 1552737795921, 6892772417281, 30597768825625, 135826834143529
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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) = 4*a(n-1) +a(n-2) +18*a(n-4) +4*a(n-5) -2*a(n-6) -8*a(n-7) -a(n-8) +a(n-10)
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EXAMPLE
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Some solutions for n=4
..1..0..0..1....0..1..1..0....1..0..1..1....1..1..0..0....0..0..1..1
..0..0..1..1....1..1..0..0....0..0..1..1....1..1..1..0....1..1..1..0
..0..0..1..1....1..0..0..1....0..0..1..1....1..0..1..1....1..1..1..0
..0..0..1..1....0..0..1..1....1..0..1..1....0..0..1..1....1..1..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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