OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..51
FORMULA
Empirical: a(n) = 4*a(n-1) +17*a(n-2) -81*a(n-3) -105*a(n-4) +675*a(n-5) +245*a(n-6) -3021*a(n-7) +198*a(n-8) +7895*a(n-9) -2282*a(n-10) -12190*a(n-11) +4928*a(n-12) +10646*a(n-13) -4768*a(n-14) -4680*a(n-15) +2016*a(n-16) +792*a(n-17) -288*a(n-18)
EXAMPLE
Some solutions for n=5
..1....2...-1....0...-2...-2....2....1....0....2....0...-2...-1....2....1...-1
..2....0....2....0....1....0....1...-2....0....1...-1....0....2....0....0...-2
..0...-2...-1....0...-2....2....2....0....0....0....0....2....1....0....0...-1
..1....0...-2....1...-1....0...-1...-2...-1...-2...-1....0....0...-2...-2....0
..0...-2...-1....0...-2...-2...-2....1....0...-1....0....2....1....0...-1...-2
..2....1....2...-2...-1....1...-1....2....2...-2....1....0....0....0...-2....0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Apr 16 2012
STATUS
approved