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A223694
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Petersen graph (8,2) coloring a rectangular array: number of 3Xn 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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%I #4 Mar 25 2013 13:57:59
%S 4096,3888,37008,363600,3788640,40075632,427910688,4599435024,
%T 49661922528,537886587312,5838098127264,63455538372048,
%U 690372511036128,7515830878003440,81857442742673184,891795388496947344
%N Petersen graph (8,2) coloring a rectangular array: number of 3Xn 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
%C Row 3 of A223692
%H R. H. Hardin, <a href="/A223694/b223694.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 13*a(n-1) +15*a(n-2) -391*a(n-3) -399*a(n-4) +1739*a(n-5) +205*a(n-6) -2013*a(n-7) +580*a(n-8) +396*a(n-9) -144*a(n-10) for n>12
%e Some solutions for n=3
%e .15..7..0...11..3..4....5.13.15....0..1..0....9.11.13...15.13.15....7..6..7
%e .15..7.15...11..3..4....5.13..5....0..1..0...13..5..6....5.13.15....7.15.13
%e .15..7..6...11..3..4....5.13.11....0..1..2....6..5..6...15..9..1....9.11.13
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 25 2013
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