A229867 Number of n X n 0..3 arrays with corresponding row and column sums equal

4, 64, 8704, 15106048, 354003288064, 115737559589453824, 542277543422445827915776

Offset

1,1

Comments

Column 3 of A229870

Links

Table of n, a(n) for n=1..7.

Example

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

Crossrefs

Sequence in context: A326868 A211214 A372813 * A362383 A051191 A120581

Adjacent sequences: A229864 A229865 A229866 * A229868 A229869 A229870

Keyword

nonn

Author

R. H. Hardin, Oct 01 2013

Status

approved