A197673 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 2,0,1,0,1 for x=0,1,2,3,4

1, 9, 57, 1111, 45162, 4268977, 924904506, 452341382317, 504191764208638

Offset

1,2

Comments

Every 0 is next to 0 2's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 1's

Diagonal of A197679

Links

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

Example

Some solutions for n=4
..0..0..0..0....2..1..1..1....0..0..0..0....0..0..0..0....1..1..1..0
..0..0..3..1....1..0..0..0....0..0..0..0....3..0..0..3....0..0..3..0
..0..3..0..1....1..0..0..3....3..0..3..0....0..0..3..0....0..0..0..0
..1..2..1..2....1..0..3..0....0..0..1..1....1..1..1..0....0..0..0..0

Crossrefs

Sequence in context: A231310 A009060 A112616 * A012089 A343133 A044147

Adjacent sequences: A197670 A197671 A197672 * A197674 A197675 A197676

Keyword

nonn

Author

R. H. Hardin Oct 17 2011

Status

approved