A193222 Number of n X n symmetric 0..4 arrays with no element equal to the sum mod 5 of any two of its horizontal and vertical neighbors

5, 64, 1212, 46984, 3644772, 576095092, 189451753044, 131372808313824, 193374015990002468

Offset

1,1

Links

Table of n, a(n) for n=1..9.

Example

Some solutions for 4X4
..4..1..4..1....3..0..1..0....3..0..3..4....2..0..4..3....0..1..0..2
..1..4..4..3....0..1..4..1....0..3..0..3....0..2..3..0....1..0..2..3
..4..4..4..1....1..4..4..3....3..0..1..2....4..3..0..3....0..2..0..2
..1..3..1..1....0..1..3..0....4..3..2..3....3..0..3..4....2..3..2..3

Crossrefs

Sequence in context: A302993 A266095 A255523 * A274265 A073179 A192558

Adjacent sequences: A193219 A193220 A193221 * A193223 A193224 A193225

Keyword

nonn

Author

R. H. Hardin Jul 18 2011

Status

approved