OFFSET
1,3
COMMENTS
Diagonal of A266012.
EXAMPLE
Some solutions for n=4
..0..2..2..1....0..2..2..1....0..1..2..2....0..2..2..0....0..2..2..0
..2..2..1..0....2..2..1..0....1..2..2..0....2..2..1..1....2..2..1..0
..0..2..2..0....0..2..2..1....0..1..2..2....0..2..2..1....0..1..2..2
..2..2..1..1....2..2..1..0....1..2..2..0....2..2..1..0....0..2..2..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 20 2015
STATUS
approved