A223289 - OEIS

A223289

4-loop graph coloring a rectangular array: number of n X n 0..8 arrays where 0..8 label nodes of a graph with edges 0,1 1,2 2,0 0,3 3,4 4,0 0,5 5,6 6,0 0,7 7,8 8,0 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.

9, 168, 42168, 46008720, 757664837832, 53263771547091072, 56395315109321439563328, 254765586321230138822186989968, 17333186258617759005034608109179216168

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Diagonal of A223297.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..10

EXAMPLE

Some solutions for 3 X 3

..0..1..0..5....0..3..0..7....0..3..0..3....0..3..0..6....1..0..8..0

..2..0..1..0....3..0..6..0....2..0..8..0....2..0..2..0....0..3..0..5

..0..6..0..1....0..2..0..6....0..1..0..1....0..8..0..1....4..0..4..0