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