A251142 Number of (n+1) X (n+1) 0..2 arrays with every 2 X 2 subblock summing to 4 and no 2 X 2 subblock having exactly two nonzero entries.

13, 49, 143, 401, 1061, 2763, 7101, 18193, 46575, 119441, 307045, 791499, 2045725

Offset: 1

Author

R. H. Hardin, Nov 30 2014

Keywords

• nonn

Comments

Diagonal of A251149.

Examples

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

Crossrefs

Cf. A251149.