A213798 Number of n X n 0..6 symmetric arrays with every row summing to 3*n.

1, 7, 153, 23753, 22698959, 138198204339

Offset: 1

Author

R. H. Hardin Jun 20 2012

Keywords

• nonn

Comments

Column 6 of A213800

Examples

			Some solutions for n=4
..3..1..2..6....0..0..6..6....0..3..3..6....6..6..0..0....3..5..1..3
..1..5..2..4....0..5..1..6....3..4..4..1....6..2..3..1....5..6..0..1
..2..2..6..2....6..1..5..0....3..4..1..4....0..3..3..6....1..0..5..6
..6..4..2..0....6..6..0..0....6..1..4..1....0..1..6..5....3..1..6..2