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A030636 Numbers with 18 divisors. 9
180, 252, 288, 300, 396, 450, 468, 588, 612, 684, 700, 768, 800, 828, 882, 972, 980, 1044, 1100, 1116, 1280, 1300, 1332, 1452, 1476, 1548, 1568, 1575, 1692, 1700, 1792, 1900, 1908, 2028, 2124, 2156, 2178, 2196, 2205, 2300, 2412, 2420, 2450 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers of the form p^17, p*q^8, p*q^2*r^2 or p^2*q^5, where p, q and r are distinct primes. - R. J. Mathar, Mar 01 2010

LINKS

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

MATHEMATICA

Select[Range[2500], DivisorSigma[0, #]==18&]  - Harvey P. Dale, Feb 01 2011

PROG

(PARI) is(n)=numdiv(n)==18 \\ Charles R Greathouse IV, Jun 19 2016

CROSSREFS

Sequence in context: A068545 A068403 A289056 * A179643 A160134 A135193

Adjacent sequences:  A030633 A030634 A030635 * A030637 A030638 A030639

KEYWORD

nonn

AUTHOR

Jeff Burch

EXTENSIONS

882 inserted, Mar 26 2007

STATUS

approved

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Last modified July 21 20:44 EDT 2017. Contains 289648 sequences.