A193614 Number of n X n symmetric 0..7 arrays with no element equal to the sum mod 8 of all its horizontal and vertical neighbors

7, 343, 117649, 282480208, 4747561627592, 558545864083284007

Offset

1,1

Links

Table of n, a(n) for n=1..6.

Example

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

Crossrefs

Sequence in context: A154024 A013712 A109493 * A194504 A347505 A015479

Adjacent sequences: A193611 A193612 A193613 * A193615 A193616 A193617

Keyword

nonn

Author

R. H. Hardin Jul 31 2011

Status

approved