A190474 Numbers with prime factorization pqr^2s^6.
20160, 31680, 33600, 37440, 44352, 47040, 48960, 52416, 52800, 54720, 62400, 66240, 68544, 76608, 81600, 82368, 83520, 89280, 91200, 92736, 102060, 103488, 106560, 107712, 110400, 116160, 116928, 118080, 120384, 122304, 123200, 123840
Offset: 1
Keywords
Links
- T. D. Noe, Table of n, a(n) for n = 1..1000
- Will Nicholes, Prime Signatures
Programs
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Mathematica
f[n_]:=Sort[Last/@FactorInteger[n]]=={1,1,2,6}; Select[Range[300000],f] -
PARI
list(lim)=my(v=List(),t1,t2,t3); forprime(p=2,sqrtnint(lim\60, 6), t1=p^6; forprime(q=2,sqrtint(lim\(6*t1)), if(q==p, next); t2=q^2*t1; forprime(r=2,lim\(2*t2), if(r==p || r==q, next); t3=r*t2; forprime(s=2,lim\t3, if(s==p || s==q || s==r, next); listput(v, t3*s))))); Set(v) \\ Charles R Greathouse IV, Aug 25 2016