A197641 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,2,2,0,2 for x=0,1,2,3,4

1, 2, 82, 2910, 407810, 243912221, 520354155777, 3409407617142917, 73436526718582338337

Offset

1,2

Comments

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

Diagonal of A197648

Links

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

Example

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

Crossrefs

Sequence in context: A307583 A061994 A332584 * A093666 A246002 A063270

Adjacent sequences: A197638 A197639 A197640 * A197642 A197643 A197644

Keyword

nonn

Author

R. H. Hardin Oct 16 2011

Status

approved