OFFSET
1,1
COMMENTS
Column 3 of A220386.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) + 8*a(n-2) + 3*a(n-3) - 3*a(n-4) - 2*a(n-5).
Empirical g.f.: x*(4 + 9*x + 4*x^2 - 3*x^3 - 3*x^4) / (1 - 4*x - 8*x^2 - 3*x^3 + 3*x^4 + 2*x^5). - Colin Barker, Jul 31 2018
EXAMPLE
Some solutions for n=3:
..0..0..1....0..0..1....0..0..1....1..1..1....0..0..1....1..1..1....1..1..0
..0..1..0....0..1..1....1..1..0....1..1..1....0..1..1....1..0..0....1..0..0
..1..0..0....1..1..0....0..0..1....1..0..0....0..1..1....0..0..1....0..0..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 13 2012
STATUS
approved