OFFSET
1,3
COMMENTS
Diagonal of A280069.
EXAMPLE
Some solutions for n=4
..0..0..1..1. .0..0..0..1. .0..0..1..1. .0..0..0..1. .0..0..0..0
..0..0..1..1. .0..0..1..1. .0..0..1..1. .0..0..1..1. .0..0..0..0
..0..0..0..0. .0..0..1..1. .0..0..1..1. .1..1..0..0. .1..1..1..0
..0..0..0..0. .0..0..0..0. .0..0..1..1. .1..0..0..0. .1..1..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 25 2016
STATUS
approved