OFFSET
1,2
COMMENTS
Diagonal of A209610
EXAMPLE
Some solutions for n=4
..1..1..1..2....2..1..1..1....2..1..1..1....2..1..1..1....1..2..1..1
..2..2..1..1....1..1..1..1....2..2..2..2....2..1..2..2....1..2..1..2
..1..2..2..2....2..2..1..2....2..1..1..2....2..1..2..2....1..2..2..2
..1..2..1..1....2..2..2..2....2..2..1..2....2..2..2..2....1..1..1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 10 2012
STATUS
approved