OFFSET
1,1
COMMENTS
Column 2 of A219299.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/12)*n^4 - (2/3)*n^3 + (53/12)*n^2 - (17/6)*n - 3 for n > 2.
Conjectures from Colin Barker, Jul 25 2018: (Start)
G.f.: x*(3 - 8*x + 12*x^2 - 10*x^3 + 2*x^4 + 5*x^5 - 2*x^6) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n > 7.
(End)
EXAMPLE
Some solutions for n=3:
2 2 1 0 1 1 0 0 1 1 0 0 0 0 0 0 0 0 0 0
2 2 0 0 1 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0
2 2 0 0 0 0 1 1 1 2 2 2 0 2 1 2 0 0 0 1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 17 2012
STATUS
approved