A137487 - OEIS

A137487

Numbers with 24 divisors.

360, 420, 480, 504, 540, 600, 630, 660, 672, 756, 780, 792, 864, 924, 936, 990, 1020, 1050, 1056, 1092, 1120, 1140, 1152, 1170, 1176, 1188, 1224, 1248, 1350, 1368, 1380, 1386, 1400, 1404, 1428, 1470, 1500, 1530, 1540, 1596, 1632, 1638, 1650, 1656, 1710

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OFFSET

1,1

COMMENTS

Maple implementation: see A030513.

Numbers of the form p^23, p^2*q^7, p*q^2*r^3 (like 360, 504), p*q*r^5 (like 480, 672), p*q*r*s^2 (like 420, 660), p^3*q^5 (like 864) or p*q^11, where p, q, r and s are distinct primes. - R. J. Mathar, Mar 01 2010

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

FORMULA

A000005(a(n))=24.

MATHEMATICA

Select[Range[3000], DivisorSigma[0, #]==24&] (* Vladimir Joseph Stephan Orlovsky, May 05 2011 *)

PROG

(PARI) is(n)=numdiv(n)==24 \\ Charles R Greathouse IV, Jun 19 2016

CROSSREFS

Cf. A030513-A030516, A030626, A030627, A030634-A030638, A005179, A003680, A096932, A061286, A061283.

Sequence in context: A185641 A352225 A031966 * A069478 A060665 A323024

Adjacent sequences: A137484 A137485 A137486 * A137488 A137489 A137490

KEYWORD

nonn

AUTHOR

R. J. Mathar, Apr 22 2008

STATUS

approved