OFFSET
1,2
COMMENTS
Superdiagonal 3 of A267328.
EXAMPLE
Some solutions for n=4
..0..1..1..2..2..3..0....0..1..1..2..2..3..3....0..0..1..1..2..2..3
..0..1..1..2..3..3..3....1..1..2..2..3..3..0....3..0..1..1..2..3..3
..0..1..2..2..3..3..0....0..1..2..2..3..0..0....0..0..1..2..2..3..3
..0..1..1..2..2..3..0....0..1..2..3..3..0..1....0..1..1..2..2..3..0
CROSSREFS
KEYWORD
nonn,more
AUTHOR
R. H. Hardin, Jan 13 2016
STATUS
approved