OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..13
EXAMPLE
Some solutions for n=4
..1........1........1........1........1........0........1........1
..1.0......1.0......3.1......1.2......2.2......2.2......2.2......1.1
..2.3.1....1.3.1....2.4.1....2.2.2....1.3.1....2.3.2....1.3.0....3.3.0
..2.3.3.1..2.1.1.1..2.1.3.1..2.3.2.1..2.1.2.0..1.1.2.0..0.2.1.1..2.3.1.1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Sep 25 2011
STATUS
approved