A067215 Number of n X n 0..7 matrices with all row and column sums equal.

1, 8, 64, 10088, 82112704, 32701809796548, 664942846307414508064, 717494365786942428294915062416

Offset

0,2

Links

Table of n, a(n) for n=0..7.

Example

Some solutions for n=3
..5..6..2....6..7..4....6..0..4....5..2..1....3..2..5....2..1..5....4..7..5
..3..4..6....6..4..7....0..4..6....3..4..1....4..1..5....5..2..1....7..2..7
..5..3..5....5..6..6....4..6..0....0..2..6....3..7..0....1..5..2....5..7..4

Crossrefs

Column 7 of A202784.

Sequence in context: A132545 A034376 A202783 * A307436 A067685 A304306

Adjacent sequences: A067212 A067213 A067214 * A067216 A067217 A067218

Keyword

nonn

Author

R. H. Hardin, Feb 20 2002

Extensions

a(0)=1 prepended and a(6)-a(7) from Andrew Howroyd, May 11 2020

Status

approved