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A237915
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Number of (n+1)X(1+1) 0..3 arrays with the upper median plus the lower median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one
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1
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256, 1584, 9892, 63476, 406468, 2591160, 16574240, 105734776, 676470380, 4314907116, 27605297244, 176086915376, 1126539110360, 7185841737072, 45972584759476, 293245625954804, 1876081040647348, 11966954890116312
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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) = 9*a(n-2) +1028*a(n-4) +10373*a(n-6) +27367*a(n-8) -32996*a(n-10) -169776*a(n-12) -127168*a(n-14) +64512*a(n-16) +589824*a(n-18)
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EXAMPLE
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Some solutions for n=4
..0..1....1..1....3..0....2..1....3..3....0..3....3..2....2..1....0..1....0..2
..3..1....1..2....0..0....2..0....2..2....2..3....0..0....2..2....3..2....3..0
..2..0....0..2....1..1....0..2....2..3....1..2....2..1....1..1....0..0....0..3
..0..2....2..2....3..0....1..0....3..2....3..1....1..1....2..1....1..1....1..1
..2..1....1..0....2..1....1..3....1..2....0..3....0..0....0..3....1..2....2..3
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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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