OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
EXAMPLE
Some solutions for n=7:
.-3....2....0...-1...-3....3....1....3...-1....3....0...-2....1...-3....0...-3
.-3....3...-2...-1....1....1...-1....2...-3....3....1....3....3...-2....0....3
.-3....0....3...-2...-1....0...-2...-2....1....1...-2...-3....0....1....2....0
..3...-3...-2....2...-1...-1....3...-2....2...-2....2....3....2....0...-3....0
..3....2....3....1....3....1....0....0....0...-2...-2....2...-1....3...-2....0
..3...-3....1....0....1...-1....1....2...-1...-3....3...-3...-3....2....0...-3
..0...-1...-3....1....0...-3...-2...-3....2....0...-2....0...-2...-1....3....3
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 05 2011
STATUS
approved