login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Petersen graph (3,1) coloring a rectangular array: number of nX6 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 05:35:20

%S 243,44217,8410671,1609602003,308267930115,59043582882099,

%T 11308909481307639,2166053304537606339,414875312906229086427,

%U 79463200007529976606227,15219994937262513427990431

%N Petersen graph (3,1) coloring a rectangular array: number of nX6 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 Column 6 of A223556

%H R. H. Hardin, <a href="/A223554/b223554.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 229*a(n-1) -7630*a(n-2) +89386*a(n-3) -465129*a(n-4) +1124537*a(n-5) -1178896*a(n-6) +505856*a(n-7) -65536*a(n-8) for n>9

%e Some solutions for n=3

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Mar 22 2013