OFFSET
1,2
COMMENTS
Column 2 of A199647.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = 3*a(n-1) +7*a(n-2) +8*a(n-3) -8*a(n-5) for n>7.
Empirical g.f.: x*(1 - 3*x^2 - 8*x^3 - 7*x^4 + 4*x^5 + 4*x^6) / (1 - 3*x - 7*x^2 - 8*x^3 + 8*x^5). - Colin Barker, May 16 2018
EXAMPLE
Some solutions for n=3:
..0..1....0..0....0..0....0..1....0..0....0..0....0..0....0..1....0..0....0..0
..0..1....0..0....1..0....0..1....1..1....1..1....1..0....0..1....0..1....0..1
..0..1....1..1....1..0....2..2....1..1....2..2....1..1....1..1....0..1....1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 08 2011
STATUS
approved