A179691 Numbers p^5*q^2*r where p, q, r are 3 distinct primes.

1440, 2016, 2400, 3168, 3744, 4704, 4860, 4896, 5472, 5600, 6624, 6804, 7840, 8352, 8800, 8928, 10400, 10656, 10692, 11616, 11808, 12150, 12384, 12636, 13536, 13600, 15200, 15264, 16224, 16524, 16992, 17248, 17568, 18400, 18468, 19296, 19360

Offset

1,1

Links

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

Will Nicholes, Prime Signatures

Index to sequences related to prime signature

Mathematica

f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 2, 5}; Select[Range[20000], f]

Prog

(PARI) list(lim)=my(v=List(), t1, t2); forprime(p=2, (lim\12)^(1/5), t1=p^5; forprime(q=2, sqrt(lim\t1), if(p==q, next); t2=t1*q^2; forprime(r=2, lim\t2, if(p==r||q==r, next); listput(v, t2*r)))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Jul 24 2011

Crossrefs

Part of the list A178739 .. A179696 (and A030514 .. A030629, A189982 .. A189990 etc, cf. A101296). - M. F. Hasler, Jul 17 2019

Subsequence of A175746 (numbers with 36 divisors).

Sequence in context: A174277 A063846 A252186 * A078095 A157508 A061221

Adjacent sequences: A179688 A179689 A179690 * A179692 A179693 A179694

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Jul 24 2010

Extensions

Name improved by M. F. Hasler, Jul 17 2019

Status

approved