OFFSET
1,3
COMMENTS
Column 2 of A297876.
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-4)
EXAMPLE
Some solutions for n=7
..0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0. .0..0
..0..0. .0..0. .0..0. .0..0. .1..0. .0..0. .0..0. .1..0. .1..0. .1..0
..0..0. .1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .1..1
..0..0. .1..1. .1..0. .1..1. .1..0. .1..0. .1..1. .0..0. .0..1. .0..0
..0..0. .1..1. .0..0. .0..0. .0..0. .0..0. .1..1. .0..0. .0..0. .0..0
..1..1. .1..1. .1..0. .0..1. .0..1. .1..1. .0..0. .0..0. .1..0. .1..1
..1..1. .1..1. .1..1. .1..1. .1..1. .1..1. .0..0. .0..0. .1..1. .1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 07 2018
STATUS
approved