OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 7*a(n-1) + 10*a(n-2) + 38*a(n-3) - 132*a(n-4) - 232*a(n-5) - 448*a(n-6) + 320*a(n-7) + 256*a(n-8).
Empirical g.f.: 2*x^2*(3 - 10*x - 7*x^2 - 58*x^3 + 108*x^4 + 192*x^5 + 64*x^6) / (1 - 7*x - 10*x^2 - 38*x^3 + 132*x^4 + 232*x^5 + 448*x^6 - 320*x^7 - 256*x^8). - Colin Barker, Sep 24 2018
EXAMPLE
Some solutions for n=3:
..0..2....0..3....0..2....0..0....0..0....0..1....0..1....0..2....0..2....0..2
..3..1....2..1....1..3....1..3....1..3....3..2....2..3....1..3....3..1....3..1
..0..0....3..0....2..2....2..0....0..2....1..0....1..0....0..0....2..2....2..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 02 2013
STATUS
approved