OFFSET
1,3
COMMENTS
Watson showed that a(n) <= 8 for all n.
It is likely that a(n) <= 6 for all n (see A193107).
LINKS
H. E. Salzer and N. Levine, Proof that every integer <= 452,479,659 is a sum of five numbers of the form Q_x = (x^3+5x)/6, x>= 0, Math. Comp., (1968), 191-192.
G. L. Watson, Sums of eight values of a cubic polynomial, J. London Math. Soc., 27 (1952), 217-224.
MAPLE
t1:=[seq((n^3-7*n)/6, n=3..20)];
LAGRANGE(t1, 8 120); # the LAGRANGE transform of a sequence is defined in A193101 - N. J. A. Sloane, Jul 15 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jul 15 2011
STATUS
approved