OFFSET
1,1
COMMENTS
Column 3 of A208314.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-1) - 3*a(n-2).
Conjectures from Colin Barker, Jun 30 2018: (Start)
G.f.: 2*x*(2 - x) / (1 - 5*x + 3*x^2).
a(n) = (2^(-n)*((5-sqrt(13))^n*(-7+sqrt(13)) + (5+sqrt(13))^n*(7+sqrt(13)))) / (3*sqrt(13)).
(End)
EXAMPLE
Some solutions for n=4:
..0..1..0....0..0..0....0..1..1....0..1..1....0..1..1....0..1..0....0..0..0
..1..0..1....1..0..1....1..0..1....1..0..0....0..1..0....1..0..1....0..1..1
..0..1..0....0..1..0....1..1..0....1..1..1....0..1..1....1..0..1....1..0..1
..1..0..1....0..0..1....1..0..1....1..0..1....0..1..0....1..1..0....0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 25 2012
STATUS
approved