OFFSET
1,3
COMMENTS
Diagonal of A216460
EXAMPLE
Some solutions for n=4
..0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x....0..x..1..x
..x..2..x..3....x..2..x..3....x..2..x..3....x..2..x..3....x..2..x..3
..3..x..1..x....3..x..4..x....4..x..0..x....3..x..4..x....0..x..1..x
..x..4..x..2....x..5..x..2....x..1..x..3....x..1..x..2....x..4..x..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Sep 07 2012
STATUS
approved