A056758 Numbers n for which d(n)^3 < n.

11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 49, 53, 59, 61, 65, 67, 69, 71, 73, 74, 77, 79, 82, 83, 85, 86, 87, 89, 91, 93, 94, 95, 97, 101, 103, 106, 107, 109, 111, 113, 115, 118, 119, 121, 122, 123, 125, 127, 129, 131, 133, 134, 137, 139, 141, 142, 143, 145, 146

Offset

1,1

Comments

The complementary set (d^3 > n) is finite, albeit with very large terms. See also d(n)^2 < n, A035035.

The last number not in this sequence is 27935107200. - Charles R Greathouse IV, Feb 27 2017

Links

Table of n, a(n) for n=1..60.

Formula

d(n)^3 = A000005(n)^3 < n.

Example

n=254, d(n)=4, d^3 = 64 < 254 so 254 is in the sequence.

Prog

(PARI) is(n)=numdiv(n)^3 < n \\ Charles R Greathouse IV, Feb 25 2017

Crossrefs

Cf. A035033-A035035, A034884.

Sequence in context: A191599 A084374 A063193 * A322273 A096489 A008364

Adjacent sequences: A056755 A056756 A056757 * A056759 A056760 A056761

Keyword

nonn,easy

Author

Labos Elemer, Aug 16 2000

Extensions

Erroneous linear recurrence signature link deleted by Harvey P. Dale, Jun 25 2021

Status

approved