OFFSET
1,1
COMMENTS
Row 4 of A201811.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 4*n^3 + 14*n + 1.
Conjectures from Colin Barker, May 25 2018: (Start)
G.f.: x*(19 - 15*x + 21*x^2 - x^3) / (1 - x)^4.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>4.
(End)
EXAMPLE
Some solutions for n=21:
-6 15 -3 -8 -13 1 13 16 15 -15 3 -21 -6 8 -11 1
9 -12 8 9 9 21 -2 -18 13 9 -7 12 3 20 -18 18
4 -18 16 -17 -13 -14 -13 9 -20 21 -16 19 -11 -7 21 -15
-7 15 -21 16 17 -8 2 -7 -8 -15 20 -10 14 -21 8 -4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 05 2011
STATUS
approved