OFFSET
1,1
COMMENTS
Column 7 of A224559.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) - 6*a(n-2) + 5*a(n-3) - 4*a(n-4) + 3*a(n-5) - a(n-6) for n>8.
Empirical g.f.: x*(669 - 2184*x + 2666*x^2 - 2124*x^3 + 1928*x^4 - 1299*x^5 + 332*x^6 + 5*x^7) / ((1 - x)^3*(1 - x - x^3)). - Colin Barker, Sep 01 2018
EXAMPLE
Some solutions for n=3:
..1..1..1..1..0..0..0..0..0....0..0..0..0..0..1..0..0..0
..0..0..0..0..0..0..0..0..0....0..0..0..0..0..1..0..0..0
..0..0..0..0..0..0..0..0..0....0..0..0..0..0..1..0..0..1
..0..0..0..0..0..0..0..0..0....0..0..0..0..0..1..0..0..1
..0..0..1..1..1..1..1..1..1....0..0..0..0..0..1..0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 10 2013
STATUS
approved