OFFSET
1,3
COMMENTS
Column 3 of A271517.
EXAMPLE
Some solutions for n=4
.....0........0........0........0........0........0........0........0
....1.0......1.2......0.0......1.1......0.0......1.1......1.2......1.1
...0.0.1....3.1.1....0.1.2....1.1.2....1.2.0....2.2.0....2.1.1....2.2.1
..2.0.0.2..3.3.1.2..0.1.3.2..1.3.3.1..1.2.1.1..2.2.3.0..1.2.1.1..0.0.1.1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 09 2016
STATUS
approved