OFFSET
1,3
COMMENTS
Column 2 of A271517.
EXAMPLE
Some solutions for n=4
.....0........0........0........0........0........0........0........0
....1.0......1.2......1.1......1.0......0.0......1.0......1.0......0.1
...0.0.0....2.2.2....1.1.0....2.0.0....0.1.1....1.1.1....1.1.2....1.2.1
..1.2.0.2..0.0.2.1..2.0.1.0..2.0.2.0..1.1.0.2..0.2.2.2..2.2.1.1..2.2.2.2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 09 2016
STATUS
approved