OFFSET
1,4
COMMENTS
Row 7 of A215788
EXAMPLE
Some solutions for n=4
..0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x
..x..2..x..4....x..2..x..3....x..2..x..3....x..2..x..4....x..2..x..4
..3..x..5..x....4..x..5..x....4..x..5..x....3..x..5..x....3..x..5..x
..x..6..x..7....x..6..x..7....x..6..x..7....x..6..x..8....x..6..x..8
..8..x..9..x....8..x..9..x....8..x..9..x....7..x..9..x....7..x..9..x
..x.10..x.12....x.10..x.12....x.10..x.11....x.10..x.12....x.10..x.11
.11..x.13..x...11..x.13..x...12..x.13..x...11..x.13..x...12..x.13..x
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 23 2012
STATUS
approved