A193504 Number of n X n symmetric 0..7 arrays with no element equal to the product mod 8 of any two of its horizontal and vertical neighbors

8, 350, 75812, 86657138, 519573586778, 16183893186795145, 2624329648165988321828

Offset

1,1

Links

Table of n, a(n) for n=1..7.

Example

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

Crossrefs

Sequence in context: A305088 A316739 A079485 * A158363 A221044 A221163

Adjacent sequences: A193501 A193502 A193503 * A193505 A193506 A193507

Keyword

nonn

Author

R. H. Hardin Jul 29 2011

Status

approved