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) -4*a(n-3).
EXAMPLE
Some solutions for n=5
..0..1..1. .0..1..0. .0..1..1. .0..1..1. .0..1..1. .0..1..1. .0..1..0
..1..1..0. .0..1..1. .1..1..0. .1..1..1. .1..1..0. .1..1..1. .0..1..0
..1..1..1. .1..1..1. .1..1..0. .0..1..1. .0..1..0. .0..1..1. .0..1..0
..0..1..1. .0..1..1. .1..1..1. .0..1..1. .0..1..1. .1..1..0. .0..1..0
..1..1..0. .1..1..0. .1..1..0. .1..1..0. .1..1..0. .0..1..0. .0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 28 2018
STATUS
approved