OFFSET
1,1
COMMENTS
Column 2 of A194778.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..34
FORMULA
Empirical: a(n) = 3*a(n-1) +a(n-2) -7*a(n-3) +4*a(n-5).
Conjectures from Colin Barker, May 05 2018: (Start)
G.f.: x*(7 - 4*x - 17*x^2 + 4*x^3 + 12*x^4) / ((1 - x)*(1 + x)^2*(1 - 2*x)^2).
a(n) = (-3*n + 2^(n+3)*(3*n+8) + 17) / 27 for n even.
a(n) = (3*n + 2^(n+3)*(3*n+8) + 10) / 27 for n odd.
(End)
EXAMPLE
All solutions for 3 X 3 including a 2.
..0
..1.1
..1.1.2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 02 2011
STATUS
approved