login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A190106 Numbers with prime factorization p^2*q^3*r^3. 4
5400, 9000, 10584, 13500, 24696, 26136, 36504, 37044, 49000, 62424, 68600, 77976, 95832, 114264, 121000, 143748, 158184, 165375, 169000, 171500, 181656, 207576, 231525, 237276, 266200, 289000, 295704, 332024, 353736, 361000, 363096 (list; graph; refs; listen; history; text; internal format)
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]]=={2, 3, 3}; Select[Range[500000], f]

PROG

(PARI) list(lim)=my(v=List(), t1, t2); forprime(p=2, (lim\4)^(1/6), t1=p^3; forprime(q=p+1, (lim\t1)^(1/3), t2=t1*q^3; forprime(r=2, sqrt(lim\t2), if(p==r||q==r, next); listput(v, t2*r^2)))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Jul 20 2011

CROSSREFS

Cf. A179691, A179698, A179746, A189991.

Sequence in context: A224688 A328562 A126117 * A252572 A035902 A203711

Adjacent sequences:  A190103 A190104 A190105 * A190107 A190108 A190109

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, May 04 2011

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified February 26 18:29 EST 2020. Contains 332293 sequences. (Running on oeis4.)