login
Petersen graph (3,1) coloring a rectangular array: number of 4Xn 0..5 arrays where 0..5 label nodes of a graph with edges 0,1 0,3 3,5 3,4 1,2 1,4 4,5 2,0 2,5 and every array movement to a horizontal or antidiagonal neighbor moves along an edge of this graph, with the array starting at 0
1

%I #4 Mar 22 2013 05:39:58

%S 216,2187,61731,1795473,53599905,1609602003,48435199821,1458216189189,

%T 43906852932615,1322067596579721,39808646082180639,

%U 1198675626234407289,36093255426614169063,1086802077561066049509,32724639445955516294571

%N Petersen graph (3,1) coloring a rectangular array: number of 4Xn 0..5 arrays where 0..5 label nodes of a graph with edges 0,1 0,3 3,5 3,4 1,2 1,4 4,5 2,0 2,5 and every array movement to a horizontal or antidiagonal neighbor moves along an edge of this graph, with the array starting at 0

%C Row 4 of A223556

%H R. H. Hardin, <a href="/A223559/b223559.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 48*a(n-1) -663*a(n-2) +4174*a(n-3) -13683*a(n-4) +22624*a(n-5) -11071*a(n-6) -19190*a(n-7) +27600*a(n-8) -3924*a(n-9) -10466*a(n-10) +4220*a(n-11) +556*a(n-12) -224*a(n-13) for n>16

%e Some solutions for n=3

%e ..0..3..5....0..1..2....0..3..4....0..1..0....0..1..4....0..1..4....0..3..5

%e ..5..3..0....4..1..2....0..1..2....4..1..4....4..5..2....4..1..4....5..2..5

%e ..4..1..0....2..5..4....4..1..2....2..5..2....4..5..2....4..1..4....5..4..5

%e ..2..1..4....4..5..4....2..5..2....2..0..3....3..0..2....4..1..0....1..2..5

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 22 2013