OFFSET
1,2
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-2) + 28*a(n-3) + 80*a(n-4) + 48*a(n-5) - 67*a(n-6) - 228*a(n-7) - 224*a(n-8).
Empirical g.f.: 2*x^2*(5 + 26*x + 21*x^2 - 28*x^3 - 106*x^4 - 104*x^5) / ((1 + x + 7*x^2)*(1 - x - 10*x^2 - 11*x^3 + x^4 + 28*x^5 + 32*x^6)). - Colin Barker, Oct 06 2018
EXAMPLE
Some solutions for n=5:
..0..1..0..0..1..0....2..1..2..0..1..0....2..1..0..2..1..0....2..1..0..0..1..2
..2..0..1..2..1..2....0..1..0..2..1..0....0..1..2..2..1..2....2..1..1..2..1..0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 02 2013
STATUS
approved