A185426 Number of (n+2)X(n+2) 0..7 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order.

6842284, 21536560306, 84722449466168, 378372621022753476, 1812817799965228636502, 9008824580891342846197566, 45497009931939204350899288292

Offset: 1

Author

R. H. Hardin Jan 27 2011

Keywords

• nonn

Comments

Diagonal of A185435

Examples

			Some solutions for 4X4
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..0..0..4....0..0..0..0....0..0..0..0....0..0..0..4....0..0..0..4
..0..1..5..2....0..1..4..6....0..0..0..2....0..0..7..3....0..0..6..6
..0..3..7..5....0..2..7..1....2..4..6..5....0..5..4..5....0..7..2..0