OFFSET
1,1
COMMENTS
Column 2 of A282647.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = a(n-1) +3*a(n-2) +4*a(n-3).
G.f.: -x*(4+7*x+4*x^2)/(-1+x+3*x^2+4*x^3) . - R. J. Mathar, Feb 28 2017
EXAMPLE
Some solutions for n=4
..0..0. .0..0. .0..0. .1..1. .0..0. .0..1. .0..1. .0..1. .1..1. .0..0
..1..0. .0..1. .0..1. .0..0. .0..0. .1..0. .0..0. .0..1. .0..0. .0..0
..1..0. .0..1. .0..0. .0..0. .0..1. .0..0. .0..0. .0..0. .0..1. .0..0
..0..0. .0..0. .1..0. .0..1. .0..0. .0..0. .1..0. .1..0. .0..0. .0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 20 2017
STATUS
approved