A223248 Two-loop graph coloring a rectangular array: number of n X n 0..4 arrays where 0..4 label nodes of a graph with edges 0,1 1,2 2,0 0,3 3,4 4,0 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.

5, 52, 2172, 307144, 200258884, 465277782336, 5036570504598960, 194136255385117730696, 34835929955107905273340132, 22243413468977139564311499153224, 66105120187260568220771918409079162896

Offset: 1

Author

R. H. Hardin Mar 18 2013

Keywords

• nonn

Comments

Diagonal of A223255

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..12