OFFSET
1,1
COMMENTS
Column 2 of A295253.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 2*a(n-1) + 3*a(n-2) + a(n-3) - a(n-5).
Empirical g.f.: x*(4 + 3*x + x^2 - x^3 - x^4) / ((1 + x)*(1 - 3*x - x^3 + x^4)). - Colin Barker, Feb 26 2018
EXAMPLE
Some solutions for n=7:
..0..0. .1..1. .1..1. .0..1. .0..0. .0..1. .0..1. .0..0. .0..1. .1..1
..0..0. .0..0. .0..0. .1..0. .0..1. .0..0. .1..0. .1..0. .0..0. .0..0
..0..0. .1..0. .1..0. .0..1. .0..0. .1..1. .0..0. .0..0. .1..1. .0..0
..0..1. .0..0. .0..0. .0..1. .0..0. .0..0. .1..0. .1..0. .0..0. .1..0
..1..0. .0..0. .0..0. .1..0. .0..1. .1..0. .0..1. .0..0. .0..0. .1..0
..1..1. .0..1. .0..0. .0..0. .0..0. .0..0. .1..1. .0..1. .1..0. .0..0
..1..0. .1..0. .1..1. .1..0. .1..0. .0..0. .0..1. .0..0. .0..0. .1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 18 2017
STATUS
approved