A221133 Number of n X n arrays of occupancy after each element moves to some horizontal or vertical neighbor, with no occupancy greater than 2

0, 9, 656, 643204, 4235650596, 259039174953636

Offset

1,2

Comments

Diagonal of A221139

Links

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

Example

Some solutions for n=3
..2..1..0....2..2..1....0..2..1....0..1..2....2..2..1....0..0..1....2..1..0
..1..2..1....2..0..1....2..1..0....1..0..2....1..0..2....1..1..2....2..2..1
..0..2..0....0..0..1....2..1..0....2..1..0....0..0..1....2..2..0....0..1..0

Crossrefs

Sequence in context: A081232 A020548 A091062 * A015007 A054327 A209964

Adjacent sequences: A221130 A221131 A221132 * A221134 A221135 A221136

Keyword

nonn

Author

R. H. Hardin Jan 02 2013

Status

approved