A179688 Numbers of the form p^3*q^3*r where p, q, and r are prime.

1080, 1512, 2376, 2808, 3000, 3672, 4104, 4968, 6264, 6696, 6750, 7000, 7992, 8232, 8856, 9288, 10152, 11000, 11448, 12744, 13000, 13176, 13720, 14472, 15336, 15768, 17000, 17064, 17928, 18522, 19000, 19224, 20952, 21816, 22248, 23000, 23112

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, 3, 3}; Select[Range[20000], f]

Prog

(PARI) list(lim)=my(v=List(), t1, t2); forprime(p=2, (lim\2)^(1/6), t1=p^3; forprime(q=p+1, (lim\t1)^(1/3), t2=t1*q^3; forprime(r=2, lim\t2, if(p==r||q==r, next); listput(v, t2*r)))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Jul 20 2011

Crossrefs

Sequence in context: A351672 A163562 A214621 * A159210 A250538 A281259

Adjacent sequences: A179685 A179686 A179687 * A179689 A179690 A179691

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Jul 24 2010

Status

approved