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A206263
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Number of (n+1) X 5 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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50, 64, 135, 260, 471, 800, 1296, 2010, 3012, 4376, 6197, 8576, 11637, 15512, 20358, 26342, 33658, 42512, 53139, 65788, 80739, 98288, 118764, 142514, 169920, 201384, 237345, 278264, 324641, 377000, 435906, 501950, 575766, 658016, 749407, 850676
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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) = 5*a(n-1) - 9*a(n-2) + 5*a(n-3) + 5*a(n-4) - 9*a(n-5) + 5*a(n-6) -a(n-7) for n>8.
G.f.: x*(50 - 186*x + 265*x^2 - 89*x^3 - 184*x^4 + 240*x^5 - 114*x^6 + 20*x^7) / ((1 - x)^6*(1 + x)).
a(n) = (1680 + 1044*n + 580*n^2 + 155*n^3 + 20*n^4 + n^5) / 120 for n>1 and even.
a(n) = (1800 + 1044*n + 580*n^2 + 155*n^3 + 20*n^4 + n^5) / 120 for n>1 and odd.
(End)
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EXAMPLE
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Some solutions for n=4:
..1..1..0..0..1....1..1..0..0..0....1..1..1..1..0....1..0..0..0..0
..0..1..1..0..0....1..0..0..0..0....0..0..0..0..0....1..0..0..0..0
..0..0..1..1..0....1..0..0..0..0....0..0..0..0..0....1..0..0..0..0
..1..0..0..1..1....0..0..0..0..0....0..0..0..0..0....1..0..0..0..0
..1..1..0..0..1....0..0..0..0..0....0..0..0..0..0....1..0..0..0..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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