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A197211
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Number of nX2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,3,2,1,0 for x=0,1,2,3,4
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3
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1, 2, 5, 8, 18, 37, 73, 151, 306, 621, 1266, 2572, 5231, 10641, 21637, 44006, 89497, 182008, 370158, 752797, 1530977, 3113587, 6332166, 12877865, 26190002, 53263176, 108322495, 220297841, 448024553, 911157386, 1853040797, 3768569784
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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 4's, every 1 is next to 1 3's, every 2 is next to 2 2's, every 3 is next to 3 1's, every 4 is next to 4 0's
Column 2 of A197217
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LINKS
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R. H. Hardin, Table of n, a(n) for n = 1..200
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FORMULA
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Empirical: a(n) = a(n-1) +a(n-2) +2*a(n-3) +a(n-5)
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EXAMPLE
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All solutions for n=4
..0..0....2..2....0..0....1..0....0..0....0..0....0..1....0..0
..0..1....2..2....1..0....3..1....2..2....0..0....1..3....0..0
..1..3....0..0....3..1....1..0....2..2....2..2....0..1....0..0
..0..1....0..0....1..0....0..0....0..0....2..2....0..0....0..0
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CROSSREFS
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Sequence in context: A063675 A000943 A152006 * A032063 A133147 A082630
Adjacent sequences: A197208 A197209 A197210 * A197212 A197213 A197214
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin Oct 11 2011
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STATUS
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approved
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