A197606 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,2,1,1,1 for x=0,1,2,3,4.

1, 5, 67, 3569, 545364, 273369257, 449467029436, 2390166008989465

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 1's, every 3 is next to 3 1's, every 4 is next to 4 1's.

Diagonal of A197613.

Links

Table of n, a(n) for n=1..8.

Example

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

Crossrefs

Cf. A197613.

Sequence in context: A352860 A291807 A197776 * A207979 A129963 A115764

Adjacent sequences: A197603 A197604 A197605 * A197607 A197608 A197609

Keyword

nonn,changed

Author

R. H. Hardin, Oct 16 2011

Status

approved