OFFSET
1,2
COMMENTS
Column 2 of A221229.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..65
FORMULA
Empirical: a(n) = 15*a(n-1) - 71*a(n-2) + 123*a(n-3) - 78*a(n-4) + 14*a(n-5) - 12*a(n-6) + 8*a(n-7).
Empirical g.f.: x*(1 + 4*x - 77*x^2 + 204*x^3 - 150*x^4 + 28*x^5 + 8*x^6) / (1 - 15*x + 71*x^2 - 123*x^3 + 78*x^4 - 14*x^5 + 12*x^6 - 8*x^7). - Colin Barker, Mar 14 2018
EXAMPLE
Some solutions for n=3:
..0..2....1..2....1..1....2..1....2..2....1..2....0..1....1..1....0..0....1..0
..2..0....0..1....0..2....0..2....1..1....0..2....1..1....1..0....2..2....1..2
..1..1....1..1....1..1....0..1....0..0....1..0....1..2....2..1....0..2....0..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 05 2013
STATUS
approved