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A223688
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Petersen graph (8,2) coloring a rectangular array: number of n X 4 0..15 arrays where 0..15 label nodes of a graph with edges 0,1 0,8 8,14 8,10 1,2 1,9 9,15 9,11 2,3 2,10 10,12 3,4 3,11 11,13 4,5 4,12 12,14 5,6 5,13 13,15 6,7 6,14 7,0 7,15 and every array movement to a horizontal or antidiagonal neighbor moves along an edge of this graph.
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1
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432, 12384, 363600, 10817856, 324280368, 9762152544, 294583794768, 8901308553408, 269168305340592, 8142829402619232, 246392700317804880, 7456528028109531456, 225671563725028735536, 6830216796989608170336
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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) = 59*a(n-1) - 1103*a(n-2) + 7621*a(n-3) - 16900*a(n-4).
Empirical g.f.: 144*x*(3 - 91*x + 760*x^2 - 1856*x^3) / (1 - 59*x + 1103*x^2 - 7621*x^3 + 16900*x^4). - Colin Barker, Aug 22 2018
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EXAMPLE
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Some solutions for n=3:
..6.14..6.14....0..8.10..2....4..5..4..3....6..7.15.13....2.10.12.14
..6.14..6..7...10..2.10..8....4..3.11.13...15..9.11..3...12.14..8..0
..6..7.15..9...10..8.10..2...11..9.15..7...15.13.11..9....8.10..8.14
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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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