A225729 Numbers n such that n < d(n)^(21/10), where d(n) is the number of divisors of n.

2, 3, 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 24, 28, 30, 32, 36, 40, 42, 48, 54, 56, 60, 66, 70, 72, 78, 80, 84, 90, 96, 100, 108, 112, 120, 126, 132, 140, 144, 150, 156, 160, 168, 180, 192, 210, 216, 240, 252, 264, 270, 280, 288, 300, 312, 330, 336, 360, 396

Offset

1,1

Comments

Alternatively, we could write n^10 < d(n)^21. The last odd number is a(10) = 15.

Links

T. D. Noe, Table of n, a(n) for n = 1..89 (complete sequence)

Mathematica

t = {}; Do[If[n < DivisorSigma[0, n]^(21/10), AppendTo[t, n]], {n, 10^4}]; t

Crossrefs

Cf. A034884 (n < d(n)^2), A175495 (n < 2^d(n)), A056757 (n < d(n)^3).

Cf. A225730-A225738.

Sequence in context: A363227 A225730 A256389 * A035033 A054219 A196277

Adjacent sequences: A225726 A225727 A225728 * A225730 A225731 A225732

Keyword

nonn,fini,full

Author

T. D. Noe, May 14 2013

Status

approved