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