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A185799
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Number of (n+1) X 2 0..3 arrays with every 2 X 2 subblock trace equal to some horizontal or vertical neighbor 2 X 2 subblock trace.
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2
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0, 704, 2176, 30976, 166272, 1567936, 10419200, 85438016, 615338112, 4793908736, 35590710400, 272110337728, 2043420143616, 15514205504320, 117001754129792, 885993008059136, 6692427408972672, 50629009974094016, 382657950434206720
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OFFSET
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1,2
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COMMENTS
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Column 1 of A185807.
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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) = 10*a(n-1) - 21*a(n-2) - 54*a(n-3) + 799*a(n-4) - 2466*a(n-5) + 5260*a(n-6) - 4944*a(n-7) + 3456*a(n-8).
Empirical g.f.: 64*x^2*(11 - 76*x + 375*x^2 - 934*x^3 + 1730*x^4 - 1536*x^5 + 1008*x^6) / (1 - 10*x + 21*x^2 + 54*x^3 - 799*x^4 + 2466*x^5 - 5260*x^6 + 4944*x^7 - 3456*x^8). - Colin Barker, Feb 28 2018
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EXAMPLE
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Some solutions for 3 X 2:
..1..1....0..0....1..3....0..3....3..3....3..1....0..1....1..1....0..0....3..2
..0..1....0..2....3..3....0..0....1..1....3..0....1..3....1..2....0..0....3..3
..1..2....2..2....2..1....2..0....1..3....2..0....3..2....2..2....1..0....2..3
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CROSSREFS
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Cf. A185807.
Sequence in context: A323342 A237009 A185568 * A186916 A185800 A188368
Adjacent sequences: A185796 A185797 A185798 * A185800 A185801 A185802
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin, Feb 04 2011
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STATUS
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approved
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