A213693 Half the number of (n+1) X (n+1) symmetric 0..4 arrays with no 2 X 2 subblock summing to 8.

56, 5470, 2322599, 4286833981, 34389632236877, 1199143411128185584, 181744271406372884215557, 119728593804039164010819562504

Offset: 1

Author

R. H. Hardin, Jun 18 2012

Keywords

• nonn

Comments

Column 4 of A213697.

Examples

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

Crossrefs

Cf. A213697.