OFFSET
1,1
COMMENTS
Column 2 of A224559.
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) - a(n-3) + a(n-4) - a(n-5) + 2*a(n-6) - a(n-7) for n>9.
Empirical g.f.: x*(70 - 116*x - 9*x^2 + 33*x^3 + 14*x^4 + 70*x^5 - 74*x^6 + 6*x^7 + 4*x^8) / ((1 - x)^3*(1 + x)*(1 - x - x^3)). - Colin Barker, Aug 31 2018
EXAMPLE
Some solutions for n=3:
..1..0..0..1....1..1..1..1....1..0..0..1....1..0..0..1....0..0..0..0
..0..0..0..0....0..0..0..0....1..0..0..0....1..0..0..1....1..1..1..0
..0..0..0..1....0..0..0..0....1..0..0..1....1..0..0..1....0..0..0..0
..0..0..0..1....0..0..0..0....0..0..0..1....1..0..0..1....0..0..0..0
..0..0..0..1....0..1..1..1....0..0..0..1....1..0..0..1....0..0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 10 2013
STATUS
approved