OFFSET
1,3
COMMENTS
Diagonal of A230989
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..18
EXAMPLE
Some solutions for n=6
..0..x..0..x..0..x..1....0..x..1..x..0..x..0....0..x..0..x..1..x..1
..x..1..x..1..x..0..x....x..1..x..0..x..1..x....x..1..x..0..x..0..x
..1..x..1..x..1..x..1....0..x..1..x..1..x..1....0..x..0..x..1..x..0
..x..0..x..0..x..0..x....x..0..x..1..x..0..x....x..1..x..1..x..1..x
..0..x..1..x..1..x..0....1..x..0..x..0..x..0....1..x..1..x..0..x..1
..x..1..x..0..x..1..x....x..0..x..1..x..1..x....x..0..x..0..x..0..x
..0..x..0..x..1..x..0....1..x..1..x..0..x..0....1..x..1..x..1..x..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 02 2013
STATUS
approved