OFFSET
1,1
COMMENTS
Column 4 of A186840
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..39
EXAMPLE
Some solutions for 4X6
..0..0..0..0..1..1....0..0..0..1..0..0....0..0..0..0..0..1....0..0..1..0..0..1
..0..1..0..1..1..0....0..0..0..1..1..1....0..1..0..0..1..1....0..0..0..1..1..1
..0..1..1..0..1..0....0..0..1..0..0..1....0..1..1..0..1..0....0..1..1..0..0..1
..0..1..0..0..1..1....0..1..1..0..0..1....0..0..0..1..1..0....0..1..0..0..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 27 2011
STATUS
approved