OFFSET
1,3
COMMENTS
Column 2 of A271437.
EXAMPLE
Some solutions for n=4
.....0........0........0........0........0........0........0........0
....1.0......1.0......1.1......1.0......0.1......0.0......1.0......1.2
...1.1.1....1.1.0....1.0.2....1.0.1....0.0.2....1.2.2....2.1.0....1.1.2
..1.2.0.1..1.0.1.2..0.0.0.0..2.0.1.1..0.2.0.2..1.2.0.2..0.0.0.0..1.2.2.0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 07 2016
STATUS
approved