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A206780
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Number of nX3 0..1 arrays avoiding 0 0 1 horizontally and 0 1 1 vertically
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2
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7, 49, 230, 1020, 4120, 16109, 61003, 227197, 834806, 3041436, 11009856, 39680145, 142545383, 510891025, 1827957230, 6532356532, 23322885552, 83216416445, 296774223739, 1058010185133, 3770863749966, 13437211488900, 47875876583016
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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) = 7*a(n-1) -10*a(n-2) -23*a(n-3) +57*a(n-4) +6*a(n-5) -75*a(n-6) +21*a(n-7) +34*a(n-8) -13*a(n-9) -5*a(n-10) +2*a(n-11)
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EXAMPLE
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Some solutions for n=4
..1..1..0....0..1..1....0..0..0....1..1..1....0..1..0....1..1..0....0..1..1
..1..0..1....1..1..0....0..1..1....1..1..0....1..0..1....0..0..0....0..1..1
..1..0..0....0..1..1....1..0..0....1..0..1....0..0..0....1..1..1....0..1..1
..0..1..1....1..0..0....0..0..0....1..1..0....1..1..0....0..0..0....0..1..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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