A193609 Number of n X n symmetric 0..2 arrays with no element equal to the sum mod 3 of all its horizontal and vertical neighbors

2, 6, 64, 1026, 32832, 2097152, 268435456, 68719348224, 35184372089856, 36028797018963968, 73786976297388343296

Offset

1,1

Links

Table of n, a(n) for n=1..11.

Example

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

Crossrefs

Sequence in context: A347949 A241590 A052522 * A061999 A066756 A070872

Adjacent sequences: A193606 A193607 A193608 * A193610 A193611 A193612

Keyword

nonn

Author

R. H. Hardin Jul 31 2011

Status

approved