A201802 Number of zero-sum nX7 -2..2 arrays with every element unequal to at most two horizontal and vertical neighbors.

8135, 1972115, 90062519, 10857153407, 1077779765471

Offset: 1

Author

R. H. Hardin Dec 05 2011

Keywords

• nonn

Comments

Column 7 of A201803

Examples

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