A030630 Numbers with 12 divisors.

60, 72, 84, 90, 96, 108, 126, 132, 140, 150, 156, 160, 198, 200, 204, 220, 224, 228, 234, 260, 276, 294, 306, 308, 315, 340, 342, 348, 350, 352, 364, 372, 380, 392, 414, 416, 444, 460, 476, 486, 490, 492, 495, 500, 516, 522, 525, 532, 544, 550

Offset: 1

Author

Jeff Burch

Keywords

• nonn

Comments

Numbers of the form p^11 A079395, p*q^5 A178740, p*q*r^2 A085987, or p^2*q^3 A143610, where p, q and r are distinct primes. - R. J. Mathar, Mar 01 2010, Mar 17 2010

Links

• R. J. Mathar, Table of n, a(n) for n = 1..1000

Programs

Mathematica

Select[Range[600], Length[Divisors[ # ]] == 12 &] (* Stefan Steinerberger, Apr 10 2006 *)
Select[Range[600],DivisorSigma[0,#]==12&] (* Harvey P. Dale, Jun 01 2016 *)

PARI

for(n=1, 1e3, if(numdiv(n)==12, print1(n,", "))) \\ Altug Alkan, Nov 11 2015