OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 6*a(n-1) + 28*a(n-3) + 3*a(n-4) + 49*a(n-5) + 33*a(n-6) - 34*a(n-7) - 22*a(n-8).
Empirical g.f.: x*(4 + 12*x + 18*x^2 + 18*x^3 + 67*x^4 + 11*x^5 - 50*x^6 - 22*x^7) / (1 - 6*x - 28*x^3 - 3*x^4 - 49*x^5 - 33*x^6 + 34*x^7 + 22*x^8). - Colin Barker, Feb 22 2019
EXAMPLE
Some solutions for n=5:
..0..1..1. .1..1..1. .1..1..0. .1..0..1. .0..1..0. .0..1..0. .1..0..1
..1..1..1. .1..0..0. .1..1..0. .1..0..1. .1..1..1. .0..1..1. .1..0..1
..1..0..0. .1..0..0. .0..0..0. .0..1..1. .1..0..0. .0..1..1. .1..0..1
..0..1..0. .1..1..1. .1..0..0. .0..1..1. .0..1..1. .0..1..0. .1..0..1
..1..1..1. .1..0..1. .1..1..0. .1..1..0. .0..1..0. .0..0..0. .0..1..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 22 2017
STATUS
approved