OFFSET
1,3
COMMENTS
Column 3 of A216612
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..97
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..0..x....x..3..x....x..0..x....x..0..x
..4..x..1....0..x..1....0..x..4....3..x..1....4..x..0....2..x..3....1..x..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Sep 10 2012
STATUS
approved