OFFSET
1,2
COMMENTS
Diagonal of A267629.
EXAMPLE
Some solutions for n=4
..0..0..1..1....0..0..1..2....0..0..1..2....0..0..1..2....0..0..0..1
..1..2..3..0....0..0..1..1....1..2..2..3....3..3..0..1....2..2..3..3
..3..0..1..2....1..2..3..3....3..3..0..1....1..2..2..3....1..1..2..3
..2..2..3..3....2..2..3..3....0..1..2..3....1..2..3..0....2..3..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 18 2016
STATUS
approved