OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) - a(n-2) + 6*a(n-3) - 4*a(n-4) + 2*a(n-5).
Empirical g.f.: x*(1 + 3*x + 2*x^2 - 2*x^3 + 2*x^4) / (1 - 2*x + x^2 - 6*x^3 + 4*x^4 - 2*x^5). - Colin Barker, Feb 25 2019
EXAMPLE
Some solutions for n=5:
..0..0. .0..0. .0..0. .1..1. .1..0. .0..0. .0..0. .1..0. .0..0. .1..1
..0..0. .0..1. .0..0. .0..1. .1..1. .1..1. .0..0. .1..1. .0..0. .0..1
..0..0. .1..1. .1..1. .0..0. .0..0. .1..0. .1..1. .1..1. .1..0. .0..0
..1..1. .0..0. .1..0. .1..1. .1..1. .0..0. .0..1. .1..1. .1..1. .1..0
..1..0. .0..0. .0..0. .0..1. .1..0. .0..0. .1..1. .1..0. .0..0. .1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 22 2017
STATUS
approved