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

83160, 98280, 128520, 143640, 154440, 173880, 201960, 216216, 219240, 225720, 231000, 234360, 238680, 266760, 273000, 273240, 279720, 282744, 309960, 316008, 322920, 325080, 334152, 344520, 348840, 355320, 357000, 368280, 373464, 382536

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, 3, 3}; Select[Range[600000], f]

Prog

(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

Crossrefs

Cf. A190382, A190383, A190384.

Sequence in context: A237535 A251112 A298437 * A201251 A235097 A125779

Adjacent sequences: A190382 A190383 A190384 * A190386 A190387 A190388

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, May 09 2011

Status

approved