OFFSET
1,1
COMMENTS
Diagonal of A235893.
FORMULA
Empirical: a(n) = 7*a(n-1) -14*a(n-2) +8*a(n-3).
EXAMPLE
Some solutions for n=4
..3..2..3..3..3....2..1..3..0..1....0..0..1..0..1....3..1..1..0..1
..2..3..2..2..2....2..1..3..0..1....0..0..1..0..1....3..1..1..0..1
..3..2..3..3..3....2..1..3..0..1....1..1..0..1..0....3..1..1..0..1
..2..3..2..2..2....2..1..3..0..1....1..1..0..1..0....3..1..1..0..1
..3..2..3..3..3....2..1..3..0..1....1..1..0..1..0....3..1..1..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 16 2014
STATUS
approved