A223553 Petersen graph (3,1) coloring a rectangular array: number of n X 5 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.

81, 6939, 609309, 53599905, 4715559621, 414863325945, 36498667573629, 3211064180380305, 282501632829717621, 24853807982558115945, 2186577702401491603629, 192369799106697718450305

Offset: 1

Author

R. H. Hardin, Mar 22 2013

Keywords

• nonn

Comments

Column 5 of A223556.

Examples

			Some solutions for n=3:
..0..2..5..3..0....0..1..0..1..4....0..2..1..4..5....0..2..0..3..0
..0..2..5..2..1....0..1..2..5..3....0..2..1..4..1....0..2..0..2..5
..1..4..1..2..1....2..1..2..0..1....1..4..1..2..0....1..2..1..2..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A223556.

Formula

Empirical: a(n) = 95*a(n-1) - 626*a(n-2) + 720*a(n-3) for n>4.

Empirical g.f.: 9*x*(9 - 84*x + 90*x^2 + 116*x^3) / (1 - 95*x + 626*x^2 - 720*x^3). - Colin Barker, Aug 21 2018