OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..19
EXAMPLE
Some solutions for 4X4
..0..1..0..1....0..1..2..0....0..1..0..2....0..1..0..1....0..1..2..0
..1..2..1..2....1..2..1..2....1..0..2..1....1..0..2..0....1..2..0..2
..0..1..2..0....2..1..2..1....0..2..0..2....0..2..0..1....2..0..2..1
..1..2..0..2....0..2..1..0....2..1..2..0....1..0..1..2....0..2..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Jul 20 2011
STATUS
approved