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A205187
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Number of (n+1)X2 0..1 arrays with the number of clockwise edge increases in every 2X2 subblock differing from each horizontal or vertical neighbor
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1
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16, 24, 48, 72, 144, 216, 432, 648, 1296, 1944, 3888, 5832, 11664, 17496, 34992, 52488, 104976, 157464, 314928, 472392, 944784, 1417176, 2834352, 4251528, 8503056, 12754584, 25509168, 38263752, 76527504, 114791256, 229582512, 344373768
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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-2)
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EXAMPLE
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Some solutions for n=4
..1..0....0..0....1..1....0..1....1..1....1..1....0..1....0..1....0..0....1..1
..0..1....0..0....0..0....1..1....1..1....0..1....0..1....1..0....1..0....1..1
..0..1....1..1....0..0....1..1....0..0....1..0....1..0....0..0....0..1....1..0
..1..0....1..1....0..1....0..0....0..0....0..0....0..0....0..0....1..1....0..1
..1..0....0..0....1..0....0..0....1..0....0..0....0..0....0..1....1..1....0..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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