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A197618
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Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,3,1,1,1 for x=0,1,2,3,4
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1
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0, 8, 0, 27, 27, 154, 272, 1117, 2321, 7299, 18275, 54627, 150925, 405606, 1155080, 3116256, 8868340, 23994371, 67730571, 185335502, 518769588, 1425654497, 3971507983, 10973327639, 30469831297, 84329766549, 233791763797
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OFFSET
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1,2
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COMMENTS
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Every 0 is next to 0 0's, every 1 is next to 1 3's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's
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LINKS
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FORMULA
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Empirical: a(n) = 2*a(n-2) +2*a(n-3) +19*a(n-4) +31*a(n-5) +39*a(n-6) +74*a(n-7) +82*a(n-8) -66*a(n-9) -608*a(n-10) -91*a(n-11) -672*a(n-12) +57*a(n-13) -2166*a(n-14) +1531*a(n-15) +346*a(n-16) -20*a(n-17) +50*a(n-18) -12*a(n-19) -2*a(n-20)
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EXAMPLE
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Some solutions for n=4
..2..1..0....0..2..1....2..1..2....1..3..1....0..1..2....2..1..0....1..3..1
..1..3..1....1..1..3....1..3..1....0..1..2....1..3..1....1..3..1....2..1..0
..1..3..1....3..1..1....1..3..1....2..1..2....1..3..1....1..3..1....2..1..2
..2..1..2....1..2..0....2..1..0....1..3..1....0..1..0....0..1..2....1..3..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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