A197451 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,3,0,2,2 for x=0,1,2,3,4

1, 7, 31, 583, 15825, 1097175, 168397471, 55114740895, 39081044835889

Offset

1,2

Comments

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

Diagonal of A197457

Links

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

Example

Some solutions containing all values 0 to 4 for n=4
..2..0..2..0....2..0..1..0....0..0..2..0....0..2..0..0....0..2..0..0
..0..2..4..2....0..2..3..2....0..2..3..1....2..4..2..0....1..3..2..0
..2..3..2..0....2..4..2..0....2..4..2..0....0..2..3..1....0..2..4..2
..0..1..0..2....0..2..0..2....0..2..0..0....2..0..2..0....0..0..2..0

Crossrefs

Sequence in context: A135630 A139287 A139307 * A289729 A197301 A280038

Adjacent sequences: A197448 A197449 A197450 * A197452 A197453 A197454

Keyword

nonn

Author

R. H. Hardin Oct 15 2011

Status

approved