OFFSET
1,3
COMMENTS
Every 0 is next to 0 4's, every 1 is next to 1 2's, every 2 is next to 2 3's, every 3 is next to 3 0's, every 4 is next to 4 1's.
Diagonal of A196809.
EXAMPLE
Some solutions for n=4
..0..0..0..0....0..0..1..0....0..3..0..0....0..1..0..0....0..3..0..0
..0..3..0..0....0..3..2..0....0..0..0..0....0..2..3..0....0..0..3..0
..1..2..3..0....3..0..3..0....3..0..0..3....0..3..0..3....0..0..3..0
..0..0..0..0....0..3..0..0....0..0..0..0....0..0..0..0....0..3..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Oct 06 2011
STATUS
approved