A223371 3X3 square grid graph coloring a rectangular array: number of n X n 0..8 arrays where 0..8 label nodes of the square grid graph and every array movement to a horizontal or vertical neighbor moves along an edge of this graph

9, 144, 13232, 6443888, 16589428016, 225311165173648, 16140699524652927296, 6098229223691941744426928, 12151193017016158174782862182736, 127692018720217712216017457942508673456

Offset

1,1

Comments

Diagonal of A223379

Links

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

Example

Some solutions for n=3
..2..1..4....1..4..5....4..1..4....4..3..6....4..3..4....1..4..1....8..7..8
..1..4..1....2..5..4....7..4..5....1..4..7....7..4..5....4..3..4....5..8..5
..4..5..2....5..8..7....4..5..4....2..5..4....4..5..8....3..4..1....8..7..8
Vertex neighbors:
0 -> 1 3
1 -> 0 2 4
2 -> 1 5
3 -> 0 4 6
4 -> 3 1 5 7
5 -> 4 2 8
6 -> 3 7
7 -> 6 4 8
8 -> 7 5

Crossrefs

Sequence in context: A162993 A094594 A173213 * A046529 A331329 A064091

Adjacent sequences: A223368 A223369 A223370 * A223372 A223373 A223374

Keyword

nonn

Author

R. H. Hardin Mar 19 2013

Status

approved