A181235 Number of (3*n)Xn binary matrices with all row sums equal and all column sums equal.

2, 22, 3362, 33235358, 5210265060002, 90698868503010138802

Offset: 1

Author

R. H. Hardin Oct 10 2010

Keywords

• nonn

Comments

Column 3 of A181236

Examples

			Some solutions for 9X3
..0..1..1....0..1..1....1..1..0....0..0..1....1..0..0....1..0..1....0..1..0
..0..1..1....1..0..1....1..0..1....0..1..0....0..1..0....1..0..1....1..0..0
..1..1..0....1..0..1....0..1..1....1..0..0....0..0..1....1..1..0....0..1..0
..1..1..0....1..1..0....0..1..1....1..0..0....1..0..0....1..0..1....0..1..0
..0..1..1....0..1..1....1..1..0....0..1..0....1..0..0....0..1..1....0..0..1
..1..0..1....0..1..1....1..0..1....1..0..0....0..0..1....0..1..1....1..0..0
..1..0..1....1..1..0....1..0..1....0..0..1....0..0..1....0..1..1....0..0..1
..1..1..0....1..1..0....0..1..1....0..0..1....0..1..0....1..1..0....0..0..1
..1..0..1....1..0..1....1..1..0....0..1..0....0..1..0....1..1..0....1..0..0