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A218516
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Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..3 n X 2 array.
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1
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4, 36, 236, 1528, 9858, 63592, 410218, 2646208, 17069998, 110114102, 710317326, 4582071648, 29557748082, 190669317026, 1229957991200, 7934137929012, 51181052626992, 330155610028966, 2129747655406998, 13738446168804038
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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) = 6*a(n-1) + 3*a(n-2) - 4*a(n-4) + a(n-5).
Empirical g.f.: 2*x*(2 + 6*x + 4*x^2 + 2*x^3 - x^4) / (1 - 6*x - 3*x^2 + 4*x^4 - x^5). - Colin Barker, Jul 24 2018
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EXAMPLE
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Some solutions for n=3:
..0..0....1..1....3..1....2..2....2..2....2..2....1..0....0..0....3..2....2..1
..0..0....3..3....0..0....3..2....2..1....2..1....0..0....2..0....0..0....1..1
..0..2....0..0....0..3....2..2....0..0....1..1....0..0....0..0....0..1....1..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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