OFFSET
1,1
COMMENTS
There is no constraint on which of the three primes is the largest or smallest.
Subsequence of A137487. - R. J. Mathar, Aug 01 2009
EXAMPLE
360=2^3*3^2*5. 504=2^3*3^2*7. 1188=2^2*3^3*11.
MATHEMATICA
f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 2, 3}; Select[Range[5000], f]
PROG
(PARI) list(lim)=my(v=List(), t1, t2); forprime(p=2, (lim\12)^(1/3), t1=p^3; 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 20 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Jul 31 2009
STATUS
approved