A201796 Number of zero-sum n X n -2..2 arrays with every element unequal to at most two horizontal and vertical neighbors.

1, 85, 4057, 988589, 722587629

Offset: 1

Author

R. H. Hardin Dec 05 2011

Keywords

• nonn

Comments

Diagonal of A201803

Examples

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