login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A325339
Number of divisors of n^3 that are <= n.
1
1, 2, 2, 3, 2, 5, 2, 4, 3, 6, 2, 8, 2, 6, 5, 5, 2, 9, 2, 8, 5, 6, 2, 11, 3, 6, 4, 8, 2, 17, 2, 6, 6, 6, 5, 14, 2, 6, 6, 11, 2, 17, 2, 9, 8, 6, 2, 15, 3, 10, 6, 9, 2, 13, 5, 11, 6, 6, 2, 26, 2, 6, 8, 7, 5, 18, 2, 10, 6, 17, 2, 18, 2, 6, 9, 10, 5, 19, 2, 14, 5
OFFSET
1,2
LINKS
EXAMPLE
a(10) counts these 6 divisors: 1,2,4,5,8,10.
MATHEMATICA
Table[Length[Select[Divisors[n^3], # <= n &]], {n, 1, 120}]
PROG
(PARI) a(n) = sumdiv(n^3, d, d <= n); \\ Michel Marcus, Apr 22 2019
CROSSREFS
Sequence in context: A100565 A244098 A285573 * A010846 A073023 A378772
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Apr 21 2019
STATUS
approved