A193223 Number of n X n symmetric 0..5 arrays with no element equal to the sum mod 6 of any two of its horizontal and vertical neighbors

6, 123, 5571, 643473, 194123061, 159836740359, 373087393798011, 2568694794232177467

Offset

1,1

Links

Table of n, a(n) for n=1..8.

Example

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

Crossrefs

Sequence in context: A356199 A078261 A239752 * A372920 A132507 A223112

Adjacent sequences: A193220 A193221 A193222 * A193224 A193225 A193226

Keyword

nonn

Author

R. H. Hardin Jul 18 2011

Status

approved