OFFSET
1,4
COMMENTS
Column 3 of A215745
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..27
EXAMPLE
Some solutions for n=4
..x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x....x..0..x
..1..x..2....1..x..2....1..x..2....1..x..2....1..x..2....1..x..2....1..x..2
..x..3..x....x..3..x....x..3..x....x..3..x....x..3..x....x..3..x....x..3..x
..2..x..0....2..x..1....4..x..0....4..x..5....4..x..1....0..x..1....0..x..4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Aug 22 2012
STATUS
approved