OFFSET
1,1
EXAMPLE
Some solutions for n=3
..2..2..2..3....1..0..1..1....1..3..2..0....2..3..2..1....0..2..0..2
..2..3..2..3....0..0..0..0....3..3..2..0....3..2..2..2....2..2..2..2
..2..2..3..2....1..0..1..1....2..2..2..0....2..2..3..2....0..2..3..3
..3..3..2..3....1..0..1..2....0..0..0..0....1..2..2..2....2..2..3..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 31 2012
STATUS
approved