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