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A207388
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Number of n X 5 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 1 1 0 vertically.
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1
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14, 196, 834, 2356, 5348, 10570, 18972, 31710, 50162, 75944, 110926, 157248, 217336, 293918, 390040, 509082, 654774, 831212, 1042874, 1294636, 1591788, 1940050, 2345588, 2815030, 3355482, 3974544, 4680326, 5481464, 6387136, 7407078, 8551600
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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) = (2/15)*n^5 + (55/12)*n^4 + (101/6)*n^3 + (5/12)*n^2 - (299/30)*n + 2.
G.f.: 2*x*(7 + 56*x - 66*x^2 + 6*x^3 + 6*x^4 - x^5) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)
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EXAMPLE
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Some solutions for n=4:
..1..0..1..1..0....0..0..0..0..0....1..0..0..0..0....0..1..1..1..0
..1..1..1..0..0....0..1..1..1..1....0..1..1..0..1....1..1..0..1..1
..1..1..1..1..0....0..1..1..0..0....1..1..1..0..1....1..1..1..1..0
..1..1..1..1..0....0..1..1..1..1....1..1..1..0..1....1..1..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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