OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..65
FORMULA
Empirical: a(n) = a(n-1) + 2*a(n-2) - 2*a(n-3) - a(n-4) + a(n-5) for n>13.
Empirical g.f.: x*(5 + 45*x + 76*x^2 - 115*x^3 - 181*x^4 + 233*x^5 + 76*x^6 - 109*x^7 - 22*x^8 + 38*x^9 - 12*x^10 - 2*x^12) / ((1 - x)^3*(1 + x)^2). - Colin Barker, Jan 30 2019
EXAMPLE
Some solutions for n=3:
..0..0..1. .0..0..0. .0..1..1. .0..1..1. .0..1..2. .0..1..1. .0..1..2
..2..1..0. .1..2..2. .2..0..2. .2..0..2. .2..0..2. .0..2..2. .0..1..2
..2..1..0. .2..1..1. .2..0..2. .2..1..0. .2..1..0. .2..1..1. .1..2..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 09 2016
STATUS
approved