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A233254
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Number of n X 6 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabelled 6-colorings with no clashing color pairs).
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1
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136, 166400, 220626944, 294517735424, 393427728465920, 525597937107992576, 702177183940808278016, 938080982436565861007360, 1253239344772433062871957504, 1674278572660580852636051308544
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OFFSET
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1,1
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LINKS
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FORMULA
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Empirical: a(n) = 1664*a(n-1) - 471040*a(n-2) + 44826624*a(n-3) - 1358954496*a(n-4).
Empirical g.f.: 8*x*(17 - 7488*x + 974848*x^2 - 40108032*x^3) / ((1 - 64*x)*(1 - 1600*x + 368640*x^2 - 21233664*x^3)). - Colin Barker, Oct 11 2018
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EXAMPLE
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Some solutions for n=2:
..0..1..2..1..2..4....0..1..0..2..1..0....0..1..2..1..0..3....0..1..2..1..3..5
..5..4..0..1..0..3....0..1..5..2..1..2....0..4..5..1..0..3....3..4..3..0..4..2
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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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