OFFSET
1,1
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-1) - 2*a(n-2) - 14*a(n-3) + 7*a(n-4) + 10*a(n-5) - 5*a(n-6) - 2*a(n-7) + a(n-8).
Empirical g.f.: x*(36 - 26*x - 113*x^2 + 70*x^3 + 83*x^4 - 46*x^5 - 17*x^6 + 9*x^7) / ((1 - 2*x - x^2 + x^3)*(1 - 3*x - 3*x^2 + 4*x^3 + x^4 - x^5)). - Colin Barker, Nov 15 2018
EXAMPLE
Some solutions for n=4:
..0..0..0..1..1....0..0..0..0..0....0..0..0..1..2....0..0..0..0..0
..0..1..2..2..2....0..0..1..1..0....2..2..1..1..2....0..1..1..2..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 26 2014
STATUS
approved