OFFSET
1,2
COMMENTS
Every 0 is next to 0 4's, every 1 is next to 1 3's, every 2 is next to 2 2's, every 3 is next to 3 0's, every 4 is next to 4 1's
Diagonal of A197090
EXAMPLE
Some solutions for n=4
..0..0..0..0....2..2..0..0....0..2..2..0....0..2..2..2....0..3..0..0
..0..2..2..2....2..2..0..0....0..2..2..0....0..2..0..2....0..0..1..0
..0..2..0..2....0..3..0..3....0..0..0..3....0..2..2..2....0..0..3..0
..0..2..2..2....0..0..0..0....0..0..3..0....0..0..0..0....0..0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Oct 10 2011
STATUS
approved