OFFSET
1,1
COMMENTS
Column 1 of A220177.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) +4*a(n-3) -8*a(n-4) -4*a(n-6) +8*a(n-7).
Empirical g.f.: 2*(1 - x + 2*x^2 - 4*x^3 + 4*x^6) / ((1 - 2*x)*(1 - 2*x^3)^2). - Colin Barker, Feb 18 2018
EXAMPLE
All solutions for n=3:
..1....0....1....1....0....0....0....1
..1....1....0....1....0....0....1....0
..0....0....1....1....0....1....1....0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 06 2012
STATUS
approved