OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..59
FORMULA
Empirical: a(n) = 6*a(n-1) -60*a(n-3) +79*a(n-4) +173*a(n-5) -334*a(n-6) -186*a(n-7) +504*a(n-8) +76*a(n-9) -296*a(n-10) -24*a(n-11) +48*a(n-12)
EXAMPLE
Some solutions for n=5
.-1...-1...-2...-1....2...-1...-2...-1...-1...-2....2....0...-2....1....1....0
.-2....0...-1....2....0....2...-1....0....0...-1...-2....1....0...-1....1....2
.-2...-1...-1....1....1....1...-1....1....1...-2...-2....0...-1...-1....1....2
.-1...-2...-1...-2....0....1...-1....0....2...-2....2...-1...-1...-1....1....2
.-2...-2...-2....1....1....1...-2...-1...-1....0....2...-2...-1...-1....2....2
.-2....0....1...-2....1....2....0....0....0...-1...-2....1...-2....1....2....1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Apr 16 2012
STATUS
approved