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A206265
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Number of (n+1) X 7 0..1 arrays with the number of rightwards and downwards edge increases in each 2 X 2 subblock equal to the number in all its horizontal and vertical neighbors.
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1
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105, 128, 339, 800, 1725, 3440, 6444, 11448, 19457, 31832, 50397, 77528, 116289, 170552, 245166, 346112, 480709, 657808, 888039, 1184048, 1560789, 2035808, 2629584, 3365864, 4272057, 5379624, 6724529, 8347688, 10295481, 12620264
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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) - 20*a(n-2) + 28*a(n-3) - 14*a(n-4) - 14*a(n-5) + 28*a(n-6) - 20*a(n-7) + 7*a(n-8) - a(n-9) for n>10.
Empirical g.f.: x*(105 - 607*x + 1543*x^2 - 1953*x^3 + 791*x^4 + 1135*x^5 - 1938*x^6 + 1302*x^7 - 436*x^8 + 60*x^9) / ((1 - x)^8*(1 + x)). - Colin Barker, Jun 15 2018
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EXAMPLE
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Some solutions for n=4:
..0..1..0..1..0..1..0....1..0..0..1..1..0..0....0..1..0..1..0..1..0
..1..0..1..0..1..0..1....1..1..0..0..1..1..0....1..0..1..0..1..0..1
..0..1..0..1..0..1..0....0..1..1..0..0..1..1....0..1..0..1..0..1..0
..1..0..1..0..1..0..1....0..0..1..1..0..0..1....1..0..1..0..1..0..1
..0..1..0..1..0..1..0....1..0..0..1..1..0..0....0..1..0..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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