A190466 Numbers with prime factorization pq^2r^7.

5760, 8064, 9600, 12672, 14976, 18816, 19584, 21888, 22400, 26496, 31360, 33408, 35200, 35712, 41600, 42624, 43740, 46464, 47232, 49536, 54144, 54400, 60800, 61056, 61236, 64896, 67968, 68992, 70272, 73600, 77184, 77440, 81536, 81792

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, May 10 2011

Keywords

• nonn

Links

• T. D. Noe, Table of n, a(n) for n = 1..1000
• Will Nicholes, Prime Signatures

Crossrefs

Cf. A179747, A190465.

Programs

Mathematica

f[n_]:=Sort[Last/@FactorInteger[n]]=={1,2,7}; Select[Range[150000],f]

PARI

list(lim)=my(v=List(),t1,t2);forprime(p=2, (lim\12)^(1/7), t1=p^7;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