A190292 Numbers with prime factorization pqrs^6.

6720, 10560, 12480, 14784, 16320, 17472, 18240, 22080, 22848, 24640, 25536, 27456, 27840, 29120, 29760, 30912, 35520, 35904, 38080, 38976, 39360, 40128, 41280, 41664, 42432, 42560, 45120, 45760, 47424, 48576, 49728, 50880, 51030, 51520

Offset

1,1

Links

T. D. Noe, Table of n, a(n) for n = 1..1000

Will Nicholes,Prime Signatures

Mathematica

f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 1, 1, 6}; Select[Range[100000], f]

Prog

(PARI) list(lim)=my(v=List(), t1, t2, t3); forprime(p=2, sqrtnint(lim\30, 6), t1=p^6; forprime(q=2, lim\(6*t1), if(q==p, next); t2=q*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

Crossrefs

Cf. A190115, A162144.

Sequence in context: A234242 A252602 A224689 * A164972 A190129 A345581

Adjacent sequences: A190289 A190290 A190291 * A190293 A190294 A190295

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, May 07 2011

Status

approved