A223686 Petersen graph (8,2) coloring a rectangular array: number of n X n 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 or antidiagonal neighbor moves along an edge of this graph

16, 432, 37008, 10817856, 13402129824, 74643295612752, 1976213549179804032, 244416339950128320684528, 139152886517246213927902144464, 360255300295725548907055827488837568

Offset

1,1

Comments

Diagonal of A223692

Links

R. H. Hardin, Table of n, a(n) for n = 1..11

Example

Some solutions for n=3
..8.14.12....5.13.11...14..8..0...10..8..0....1..2.10...13.15..7...12.10.12
..8.14..6...11.13.11....0..8..0...14..8..0...10.12.10....9.15.13...12.14.12
..6..7..6...11..9..1...14..8..0....0..8..0...14.12.14...13.15.13...12..4.12

Crossrefs

Sequence in context: A274731 A111921 A118994 * A000489 A075852 A260853

Adjacent sequences: A223683 A223684 A223685 * A223687 A223688 A223689

Keyword

nonn

Author

R. H. Hardin Mar 25 2013

Status

approved