A141264 Number of divisors of m^2 where m is the smallest number with exactly n divisors.
1, 3, 5, 9, 9, 15, 13, 21, 25, 27, 21, 45, 25, 39, 45, 63, 33, 75, 37, 81, 65, 63, 45, 105, 81, 75, 125, 117, 57, 135, 61, 189, 105, 99, 117, 225, 73, 111, 125, 243, 81, 195, 85, 189, 225, 135, 93, 315, 169, 243, 165, 225, 105, 375, 189, 351, 185, 171, 117, 405, 121, 183
Offset: 1
Keywords
Examples
a(8) = 21 because the smallest number with 8 divisors is 24, 24^2 = 576 and 576 has 21 divisors.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
a[n_]:=Module[{m=0},Until[DivisorSigma[0,m]==n,m++];DivisorSigma[0,m^2]];Array[a,25] (* James C. McMahon, Jul 26 2025 *)
Formula
Extensions
Extended beyond a(8) by R. J. Mathar, Sep 01 2008
Comments