OFFSET
1,1
COMMENTS
Column 4 of A190041.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..200
FORMULA
Empirical: a(n) = n^2 + 3*n - 1 for n>3.
Conjectures from Colin Barker, May 04 2018: (Start)
G.f.: x*(7 - 9*x + 3*x^2 + 2*x^3 - x^5) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>4.
(End)
EXAMPLE
Some solutions for n=3:
2 1 1 3 1 2 0 1 0 1 1 2 0 1 1 4
2 1 1 4 4 2 2 2 2 3 2 2 4 2 3 4
4 2 2 4 4 2 2 2 2 3 2 2 4 3 4 4
4 2 3 4 4 4 2 2 4 4 4 2 4 4 4 4
4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 04 2011
STATUS
approved