OFFSET
1,2
COMMENTS
Diagonal of A221290
EXAMPLE
Some solutions for n=3
..0..0..0....0..0..1....0..1..0....0..0..0....0..0..1....0..1..1....0..0..1
..1..1..0....1..0..1....0..1..0....1..0..1....0..1..0....0..1..1....1..0..1
..1..1..0....1..1..0....1..1..0....1..0..0....1..1..0....0..1..0....1..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 09 2013
STATUS
approved