OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) - a(n-2) - 3*a(n-3) + a(n-4) + a(n-5).
Empirical g.f.: 2*x^2*(1 - x^2 - 2*x^3) / ((1 - x)*(1 - x - x^2)^2). - Colin Barker, Feb 11 2019
EXAMPLE
Some solutions for n=4:
..0..0..1..0. .0..1..0..0. .0..1..1..0. .0..1..1..0. .0..1..1..0
..1..0..1..0. .1..0..1..0. .0..0..1..1. .0..1..0..1. .1..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 18 2016
STATUS
approved