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A223595
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Petersen graph (8,2) coloring a rectangular array: number of nX4 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, diagonal or antidiagonal neighbor moves along an edge of this graph
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%I #4 Mar 23 2013 06:05:43
%S 432,6736,122608,2372080,47659632,982848688,20631729648,438231627440,
%T 9379905920496,201754894742320,4353130535839216,94109174401819824,
%U 2037032269494019568,44126508340010479152,956337724569802746864
%N Petersen graph (8,2) coloring a rectangular array: number of nX4 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, diagonal or antidiagonal neighbor moves along an edge of this graph
%C Column 4 of A223599
%H R. H. Hardin, <a href="/A223595/b223595.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 45*a(n-1) -639*a(n-2) +2781*a(n-3) +4328*a(n-4) -42674*a(n-5) +32672*a(n-6) +131496*a(n-7) -190080*a(n-8) +31104*a(n-9)
%e Some solutions for n=3
%e .10.12.10.12...13.15.13..5...10..8.14.12....2..3..2.10...13.15..9.15
%e .10..8.14..8....9.11.13..5...10..8.14.12...11..3..2..3....9.11..9..1
%e .10..8.10.12....9.11.13.15....0..8.14..6....2..3..2.10...13.15..9..1
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 23 2013
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