OFFSET
1,2
COMMENTS
Superdiagonal 1 of A267553.
EXAMPLE
Some solutions for n=4
..0..0..1..1..1....0..1..1..2..3....0..1..2..2..3....0..0..1..1..2
..0..1..2..2..2....1..2..2..3..0....1..2..3..3..0....0..1..1..2..3
..1..2..3..3..3....2..2..3..0..0....2..3..0..0..1....1..2..2..3..3
..2..3..3..0..0....3..3..0..1..1....3..0..1..1..2....2..3..3..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 17 2016
STATUS
approved