A179700 Numbers of the form p^3*q^2*r*s where p, q, r, and s are distinct primes.

2520, 3780, 3960, 4200, 4680, 5544, 5880, 5940, 6120, 6552, 6600, 6840, 7020, 7800, 8280, 8316, 8568, 9180, 9450, 9576, 9828, 10200, 10260, 10296, 10440, 10500, 11160, 11400, 11592, 12420, 12852, 12936, 13230, 13320, 13464, 13800, 14364, 14520

Offset

1,1

Links

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

Will Nicholes, Prime Signatures

Index to sequences related to prime signature

Mathematica

f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 1, 2, 3}; Select[Table[n, {n, 8!}], f[ # ]&]

Prog

(PARI) list(lim)=my(v=List(), t1, t2, t3); forprime(p=2, sqrtnint(lim\60, 3), t1=p^3; 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

Crossrefs

Sequence in context: A175754 A068547 A094515 * A066531 A258540 A159214

Adjacent sequences: A179697 A179698 A179699 * A179701 A179702 A179703

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Jul 24 2010

Status

approved