OFFSET
1,2
COMMENTS
Diagonal of A269186.
EXAMPLE
Some solutions for n=3
..0..1..1. .0..2..3. .1..1..1. .3..2..3. .0..2..2. .1..1..0. .3..1..3
..1..0..0. .2..2..2. .3..1..1. .3..2..0. .0..2..3. .0..0..2. .3..2..3
..0..1..2. .2..0..3. .0..1..1. .2..2..0. .3..2..3. .0..0..0. .3..2..3
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 20 2016
STATUS
approved