OFFSET
1,1
COMMENTS
Column 3 of A205475
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 20*a(n-1) -75*a(n-2) -688*a(n-3) +5022*a(n-4) -496*a(n-5) -63723*a(n-6) +111258*a(n-7) +251463*a(n-8) -817674*a(n-9) -9180*a(n-10) +2101200*a(n-11) -1759426*a(n-12) -1578136*a(n-13) +2839836*a(n-14) -596208*a(n-15) -1049272*a(n-16) +620728*a(n-17) +18624*a(n-18) -96072*a(n-19) +24528*a(n-20) -1728*a(n-21)
EXAMPLE
Some solutions for n=4
..0..0..1..1....0..1..1..0....0..1..0..2....0..0..0..0....0..0..1..2
..2..0..1..0....1..1..0..0....1..1..0..0....1..1..0..2....1..2..1..0
..0..0..0..0....2..1..0..1....2..1..1..1....1..0..0..2....0..0..1..2
..2..2..0..1....1..1..0..0....1..1..2..1....0..0..2..2....1..2..1..0
..2..0..0..0....1..0..0..1....1..2..2..1....0..2..2..0....0..0..1..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 27 2012
STATUS
approved