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A186468
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Number of (n+1)X6 0..2 arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors
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1
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966, 903, 3190, 4875, 13278, 16083, 40626, 52755, 129102, 182841, 418022, 632281, 1362100, 2157562, 4454506, 7311254, 14630604, 24660486, 48209460, 82892994, 159253412, 277942714, 527083732, 930249586, 1747039708, 3109258106
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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*a(n-1)+a(n-2)-4*a(n-3)+4*a(n-4)-2*a(n-5) for n>14
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EXAMPLE
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Some solutions for 3X6
..2..1..0..1..0..2....1..1..0..0..0..1....1..0..0..0..1..0....0..0..0..0..0..2
..1..0..1..0..1..0....2..0..1..0..0..0....2..0..0..0..0..1....1..0..0..0..0..0
..0..1..0..1..0..1....0..2..0..1..0..0....0..2..0..0..0..0....2..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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