OFFSET
1,4
COMMENTS
Row 7 of A215870
EXAMPLE
Some solutions for n=4
..x..0..x..1....x..0..x..1....x..0..x..1....x..0..x..2....x..0..x..2
..2..x..3..x....2..x..3..x....2..x..3..x....1..x..3..x....1..x..3..x
..x..4..x..5....x..4..x..5....x..4..x..6....x..4..x..6....x..4..x..5
..6..x..7..x....6..x..7..x....5..x..7..x....5..x..7..x....6..x..7..x
..x..8..x..9....x..8..x.10....x..8..x..9....x..8..x.10....x..8..x..9
.10..x.11..x....9..x.11..x...10..x.11..x....9..x.11..x...10..x.11..x
..x.12..x.13....x.12..x.13....x.12..x.13....x.12..x.13....x.12..x.13
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 25 2012
STATUS
approved