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A223688
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.
1
432, 12384, 363600, 10817856, 324280368, 9762152544, 294583794768, 8901308553408, 269168305340592, 8142829402619232, 246392700317804880, 7456528028109531456, 225671563725028735536, 6830216796989608170336
OFFSET
1,1
COMMENTS
Column 4 of A223692.
LINKS
FORMULA
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
EXAMPLE
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
CROSSREFS
Cf. A223692.
Sequence in context: A223436 A230922 A109123 * A269183 A228105 A232905
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 25 2013
STATUS
approved