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