A197530 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 2,0,1,0,0 for x=0,1,2,3,4.

1, 9, 56, 1419, 107655, 23325250, 14991391782, 27504159228709, 145843735771766573

Offset: 1

Author

R. H. Hardin Oct 16 2011

Keywords

• nonn

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 0's

Diagonal of A197537

Examples

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