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A190385 Numbers with prime factorization pqrs^3t^3. 3

%I #10 Aug 25 2016 23:07:32

%S 83160,98280,128520,143640,154440,173880,201960,216216,219240,225720,

%T 231000,234360,238680,266760,273000,273240,279720,282744,309960,

%U 316008,322920,325080,334152,344520,348840,355320,357000,368280,373464,382536

%N Numbers with prime factorization pqrs^3t^3.

%H T. D. Noe, <a href="/A190385/b190385.txt">Table of n, a(n) for n = 1..1000</a>

%H Will Nicholes, <a href="http://willnicholes.com/math/primesiglist.htm">Prime Signatures</a>

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

%o (PARI) list(lim)=my(v=List(),t1,t2,t3,t4); forprime(p=2,sqrtnint(lim\840, 3), t1=p^3; forprime(q=2,sqrtnint(lim\(30*t1), 3), if(q==p, next); t2=q^3*t1; forprime(r=2,lim\(6*t2), if(r==p || r==q, next); t3=r*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

%Y Cf. A190382, A190383, A190384.

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, May 09 2011

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Last modified April 23 13:11 EDT 2024. Contains 371913 sequences. (Running on oeis4.)