OFFSET
1,1
COMMENTS
Column 1 of A236809.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 5*a(n-1) + 20*a(n-2) - 130*a(n-3) + 36*a(n-4) + 600*a(n-5) - 720*a(n-6).
Empirical g.f.: x*(81 - 128*x - 1972*x^2 + 4008*x^3 + 9000*x^4 - 19440*x^5) / ((1 - 2*x)*(1 - 3*x)*(1 - 6*x^2)*(1 - 20*x^2)). - Colin Barker, Feb 24 2018
EXAMPLE
Some solutions for n=5:
1 2 1 2 0 2 0 2 0 2 0 0 0 2 1 1 2 2 2 1
0 0 2 0 1 0 2 1 1 0 0 0 1 1 1 0 2 1 2 2
0 1 1 0 2 0 2 0 2 0 1 1 2 0 1 1 1 1 2 1
1 1 0 0 0 1 1 2 2 1 1 1 1 1 2 1 2 1 2 0
1 2 1 0 2 2 0 2 0 0 2 2 0 2 0 0 2 0 0 1
1 1 0 0 1 0 0 1 2 1 1 1 1 1 0 1 0 1 0 0
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 31 2014
STATUS
approved