A223595 Petersen graph (8,2) coloring a rectangular array: number of nX4 0..15 arrays where 0..15 label nodes of a graph with edges 0,1 0,8 8,14 8,10 1,2 1,9 9,15 9,11 2,3 2,10 10,12 3,4 3,11 11,13 4,5 4,12 12,14 5,6 5,13 13,15 6,7 6,14 7,0 7,15 and every array movement to a horizontal, diagonal or antidiagonal neighbor moves along an edge of this graph.

432, 6736, 122608, 2372080, 47659632, 982848688, 20631729648, 438231627440, 9379905920496, 201754894742320, 4353130535839216, 94109174401819824, 2037032269494019568, 44126508340010479152, 956337724569802746864

Offset: 1

Author

R. H. Hardin Mar 23 2013

Keywords

• nonn

Comments

Column 4 of A223599

Examples

			Some solutions for n=3
.10.12.10.12...13.15.13..5...10..8.14.12....2..3..2.10...13.15..9.15
.10..8.14..8....9.11.13..5...10..8.14.12...11..3..2..3....9.11..9..1
.10..8.10.12....9.11.13.15....0..8.14..6....2..3..2.10...13.15..9..1
		

Links

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

Formula

Empirical: a(n) = 45*a(n-1) -639*a(n-2) +2781*a(n-3) +4328*a(n-4) -42674*a(n-5) +32672*a(n-6) +131496*a(n-7) -190080*a(n-8) +31104*a(n-9)