OFFSET
1,1
COMMENTS
Diagonal of A186840
EXAMPLE
Some solutions for 4X4
..1..0..1..0....1..0..1..0....1..1..0..0....0..0..0..0....1..1..0..1
..1..0..0..1....0..0..1..1....0..0..1..1....0..0..0..1....0..0..0..1
..0..0..0..1....1..1..1..1....0..1..1..0....1..0..0..0....1..1..0..0
..1..1..0..1....1..1..0..1....1..1..0..0....1..1..1..1....0..1..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 27 2011
STATUS
approved