OFFSET
1,1
COMMENTS
Diagonal of A217637
EXAMPLE
Some solutions for n=3
..0..1..1....0..1..1....0..0..0....0..0..1....0..0..1....0..1..0....0..0..0
..0..0..0....0..0..1....0..1..0....0..0..0....0..0..1....0..0..0....0..0..0
..0..0..0....0..0..1....0..0..0....0..0..1....0..0..0....0..0..0....1..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 09 2012
STATUS
approved