OFFSET
1,2
EXAMPLE
Some solutions for n=4
..1..0..0..1....2..0..0..0....1..2..3..3....1..3..3..2....0..2..2..3
..0..1..2..2....0..1..0..1....2..3..2..0....3..2..1..0....2..1..0..1
..0..2..0..3....0..0..1..0....3..2..3..2....3..1..0..3....2..0..3..1
..1..2..3..1....0..1..0..1....3..0..2..0....2..0..3..2....3..1..1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 31 2012
STATUS
approved