OFFSET
1,2
COMMENTS
Diagonal of A280604.
EXAMPLE
Some solutions for n=4
..0..1..1..0. .0..0..0..0. .0..1..1..0. .0..1..1..0. .0..0..0..0
..1..0..1..0. .1..1..1..0. .0..0..1..1. .1..0..0..1. .1..1..1..1
..1..0..1..0. .0..0..1..1. .1..0..0..0. .1..1..1..0. .0..0..0..0
..0..1..0..1. .1..0..0..1. .1..1..1..1. .0..0..0..1. .1..1..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 06 2017
STATUS
approved