A229415 Number of n X n 0..2 zero-diagonal arrays with corresponding row and column sums equal

1, 3, 45, 4743, 3801411, 23938685973, 1215663478473627

Offset

1,2

Comments

Column 2 of A229417

Links

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

Example

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

Crossrefs

Sequence in context: A268196 A057863 A302156 * A265621 A124488 A086683

Adjacent sequences: A229412 A229413 A229414 * A229416 A229417 A229418

Keyword

nonn

Author

R. H. Hardin Sep 22 2013

Status

approved