OFFSET
1,1
COMMENTS
Diagonal of A227333.
EXAMPLE
Some solutions for n=4
..0..0..0..0....0..0..1..0....0..1..1..1....0..0..1..0....0..1..1..0
..0..0..0..0....1..1..0..0....1..0..1..1....0..0..1..0....0..1..1..0
..1..0..1..0....0..1..0..0....0..0..1..1....1..0..1..0....1..0..1..1
..0..1..0..0....0..0..0..0....0..1..0..0....1..0..0..1....0..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Jul 07 2013
STATUS
approved