OFFSET
1,2
COMMENTS
Column 2 of A270256.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..24
EXAMPLE
Some solutions for n=4
.....2........2........1........0........0........2........0........2
....2.1......2.1......2.2......0.0......1.0......2.1......1.0......2.1
...2.1.2....1.2.2....1.2.2....0.0.0....1.0.1....2.1.2....0.0.1....2.2.2
..2.2.2.1..1.2.1.2..0.2.2.1..0.1.1.0..0.0.0.0..2.2.2.2..1.0.1.2..1.1.2.2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 14 2016
STATUS
approved