A190386 Numbers with prime factorization pqr^2s^2t^3.

138600, 163800, 194040, 207900, 214200, 229320, 239400, 245700, 257400, 289800, 291060, 299880, 304920, 321300, 323400, 335160, 336600, 343980, 346500, 359100, 365400, 376200, 382200, 386100, 390600, 397800, 405720, 409500, 425880, 434700

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, May 09 2011

Keywords

• nonn

Links

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

Crossrefs

Cf. A190383, A190384, A190385.

Programs

Mathematica

f[n_]:=Sort[Last/@FactorInteger[n]]=={1,1,2,2,3};Select[Range[600000],f]

PARI

list(lim)=my(v=List(),t1,t2,t3,t4); forprime(p=2,sqrtnint(lim\1260, 3), t1=p^3; forprime(q=2,sqrtint(lim\(60*t1)), if(q==p, next); t2=q^2*t1; forprime(r=2,sqrtint(lim\(6*t2)), if(r==p || r==q, next); t3=r^2*t2; forprime(s=2,lim\(2*t3), if(s==p || s==q || s==r, next); t4=s*t3; forprime(t=2,lim\t4, if(t==p || t==q || t==r || t==s, next); listput(v, t4*t)))))); Set(v) \\ Charles R Greathouse IV, Aug 25 2016