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A067215
Number of n X n 0..7 matrices with all row and column sums equal.
2
1, 8, 64, 10088, 82112704, 32701809796548, 664942846307414508064, 717494365786942428294915062416
OFFSET
0,2
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
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