OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 6*a(n-1) - 12*a(n-2) + 5*a(n-3) + 12*a(n-4) - 12*a(n-5) - 3*a(n-6) + 6*a(n-7) - a(n-9) for n>11.
Empirical g.f.: x*(1 + 28*x - 48*x^2 - 79*x^3 + 86*x^4 + 142*x^5 - 57*x^6 - 134*x^7 + 46*x^8 + 39*x^9 - 36*x^10) / ((1 - x)^3*(1 - x - x^2)^3). - Colin Barker, Feb 13 2019
EXAMPLE
Some solutions for n=4:
..0..1..0..1. .0..1..0..1. .0..1..0..0. .0..1..1..0. .0..1..0..1
..0..0..1..0. .1..0..1..1. .1..0..1..0. .1..0..0..1. .1..0..1..1
..1..1..0..1. .0..1..0..1. .0..1..0..1. .1..0..1..1. .1..1..0..1
..0..1..0..1. .0..1..0..1. .1..0..1..1. .0..1..0..1. .0..0..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 05 2017
STATUS
approved