OFFSET
1,4
COMMENTS
Column 2 of A282838.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 3*a(n-1) +6*a(n-2) -5*a(n-3) -42*a(n-4) -33*a(n-5) +51*a(n-6) +156*a(n-7) +144*a(n-8) +64*a(n-9).
Empirical: G.f.: 16*x^4*(-1+x+3*x^2)/(4*x^3+3*x^2+x-1)^3 . - R. J. Mathar, Feb 23 2017
EXAMPLE
Some solutions for n=4
..0..1. .1..0. .1..0. .0..1. .1..0. .0..1. .0..1. .1..0. .0..1. .1..0
..1..0. .1..0. .1..0. .0..1. .1..0. .1..0. .1..0. .0..1. .0..1. .1..0
..0..1. .0..1. .1..0. .1..0. .1..0. .1..0. .0..1. .1..0. .1..0. .0..1
..0..1. .0..1. .1..0. .0..1. .0..1. .1..0. .1..0. .0..1. .1..0. .1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 22 2017
STATUS
approved