OFFSET
1,1
COMMENTS
Column 4 of A201989
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..12
EXAMPLE
Some solutions for n=2
.-3.-3.-1..3...-3.-2..0..3...-2.-1.-1..2...-2..0..0..3...-3.-2.-1..3
.-1..0..2..3...-1..0..3..0....0..1..1..0...-1.-1..2.-1...-1..2..3.-1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 07 2011
STATUS
approved