OFFSET
1,2
COMMENTS
Row 4 of A215190.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*a(n-1) - 5*a(n-2) + 5*a(n-4) - 4*a(n-5) + a(n-6).
Conjectures from Colin Barker, Jul 22 2018: (Start)
G.f.: 2*x^2*(9 + 8*x + 7*x^2) / ((1 - x)^5*(1 + x)).
a(n) = n*(3*n^3 + n^2 - 1)/3 for n even.
a(n) = (3*n^4 + n^3 - n - 3)/3 for n odd.
(End)
EXAMPLE
Some solutions for n=6:
2 4 6 0 0 6 6 2 0 0 1 6 5 4 3 3
4 3 0 4 5 0 1 3 2 4 4 0 6 5 4 5
1 5 4 0 1 6 2 5 5 1 3 4 2 6 0 3
0 1 6 3 3 3 3 1 4 5 0 3 0 0 3 4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 05 2012
STATUS
approved