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A253428
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Number of (n+1)X(n+1) 0..1 arrays with every 2X2 subblock diagonal minus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally
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0
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16, 58, 85, 156, 300, 588, 1164, 2316, 4620, 9228, 18444, 36876, 73740, 147468, 294924, 589836, 1179660, 2359308, 4718604, 9437196, 18874380, 37748748, 75497484, 150994956, 301989900, 603979788
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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) = 3*a(n-1) -2*a(n-2) for n>5
Empirical: a(n) = 9*2^n + 12 for n>3
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EXAMPLE
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Some solutions for n=4
..0..1..1..1..0....1..1..1..1..1....0..0..1..0..1....0..1..1..1..1
..1..1..1..1..0....1..1..1..1..1....1..0..1..0..1....1..1..1..1..1
..1..1..1..1..0....0..0..0..0..0....1..0..1..0..1....1..1..1..1..1
..1..1..1..1..0....0..0..0..0..0....1..0..1..0..1....0..0..0..0..0
..1..1..1..1..1....1..1..1..1..1....1..0..1..0..1....0..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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