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A205239
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Number of (n+1)X2 0..2 arrays with the number of rightwards and downwards edge increases in each 2X2 subblock differing from the number in each of its horizontal and vertical neighbors
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1
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81, 486, 2990, 18148, 111041, 677732, 4143102, 25302238, 154597952, 944323666, 5769147079, 35241970176, 215294819906, 1315202262082, 8034520991634, 49082022117918, 299838801088734, 1831687968517910, 11189641429502614
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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) = 27*a(n-2) +48*a(n-3) +35*a(n-4) +258*a(n-5) +400*a(n-6) +502*a(n-7) +1956*a(n-8) +2498*a(n-9) +333*a(n-10) +544*a(n-11) +2005*a(n-12) +980*a(n-13) -5963*a(n-14) -556*a(n-15) +1856*a(n-16) +2430*a(n-17) -2045*a(n-18) -2184*a(n-19) -4376*a(n-20) -1720*a(n-21) -448*a(n-22) -64*a(n-23) for n>24
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EXAMPLE
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Some solutions for n=4
..2..1....0..1....1..2....0..2....1..1....2..1....1..0....1..2....2..0....1..2
..0..2....2..0....1..1....0..1....0..0....0..2....2..1....0..1....2..0....2..1
..0..0....2..1....1..1....2..2....2..0....1..2....1..1....2..2....2..2....2..0
..2..1....0..2....1..2....1..0....0..2....2..1....2..1....2..0....2..0....2..2
..0..1....1..2....1..0....0..2....0..0....1..0....1..2....0..1....2..2....2..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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