OFFSET
1,2
COMMENTS
Column 2 of A202979.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) - 2*a(n-2) + 2*a(n-3) - 2*a(n-4) - a(n-5).
Empirical g.f.: x*(1 - x - 3*x^3 - x^4) / (1 - 3*x + 2*x^2 - 2*x^3 + 2*x^4 + x^5). - Colin Barker, Feb 19 2018
EXAMPLE
Some solutions for n=5:
..0..0....0..0....1..1....0..0....1..1....0..0....1..1....1..1....1..1....1..1
..0..0....1..1....1..1....1..1....1..1....0..0....1..1....1..1....1..1....1..1
..0..0....1..1....0..0....1..1....0..0....0..0....1..1....1..1....1..0....0..1
..1..1....0..0....1..1....1..1....0..0....0..0....0..0....1..1....1..1....1..1
..1..1....0..0....1..1....0..0....0..0....0..0....0..0....1..1....1..1....1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 26 2011
STATUS
approved