OFFSET
1,2
COMMENTS
Row 2 of A221200.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..86
FORMULA
Empirical: a(n) = 7*a(n-1) + 14*a(n-2) - 126*a(n-3) + 504*a(n-5) - 224*a(n-6) - 448*a(n-7) + 256*a(n-8).
Empirical g.f.: x^2*(9 - 53*x + 342*x^3 - 124*x^4 - 448*x^5 + 256*x^6) / ((1 - 2*x)*(1 + 2*x)*(1 - 7*x + 4*x^2)*(1 - 14*x^2 + 16*x^4)). - Colin Barker, Aug 04 2018
EXAMPLE
Some solutions for n=3:
..1..2..1....0..2..0....0..2..1....0..2..0....0..2..2....2..2..0....1..2..0
..0..2..0....0..2..2....0..2..1....1..2..1....0..2..0....0..2..0....1..2..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 04 2013
STATUS
approved