A201983 Number of n X n zero-sum -3..3 arrays with rows and columns lexicographically nondecreasing.

1, 77, 134217, 7375608084, 13189629907532856

Offset: 1

Author

R. H. Hardin Dec 07 2011

Keywords

• nonn

Comments

Diagonal of A201989

Examples

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