A225729 - OEIS

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

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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.