OFFSET
1,2
COMMENTS
Row 2 of A221693.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-1) + 28*a(n-2) + 9*a(n-3) - 62*a(n-4) - 30*a(n-5) + 64*a(n-6) + 32*a(n-7) - 32*a(n-8) + 32*a(n-9).
Empirical g.f.: x*(1 + 16*x + 19*x^2 - 21*x^3 - 27*x^4 + 36*x^5 + 38*x^6 - 24*x^7 + 24*x^8) / ((1 + 2*x)^2*(1 - 9*x + 4*x^2 + 11*x^3 + 2*x^4 - 22*x^5 + 16*x^6 - 8*x^7)). - Colin Barker, Aug 10 2018
EXAMPLE
Some solutions for n=3:
..2..1..1....0..2..1....1..1..0....1..2..0....2..1..0....1..0..0....0..2..1
..0..0..2....1..0..2....3..0..1....0..3..0....0..3..0....1..3..1....2..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 22 2013
STATUS
approved