OFFSET
1,3
EXAMPLE
Some solutions for n=4
..0..0..1..1....0..0..2..2....0..0..0..2....0..0..1..1....0..0..0..0
..0..0..2..0....0..1..1..1....0..1..1..2....0..0..1..0....0..1..1..0
..1..2..2..0....2..1..2..2....0..1..1..3....1..1..1..0....0..1..1..1
..1..0..0..0....2..1..2..2....2..2..3..3....1..0..0..0....0..0..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 29 2012
STATUS
approved