A115960 Numbers n having exactly 6 distinct prime factors, the largest of which is greater than or equal to sqrt(n) (i.e., sqrt(n)-rough numbers with exactly 6 distinct prime factors).

5338410, 5389230, 5403090, 5407710, 5421570, 5430810, 5444670, 5477010, 5490870, 5500110, 5504730, 5518590, 5527830, 5541690, 5569410, 5583270, 5597130, 5629470, 5638710, 5652570, 5680290, 5698770, 5712630, 5721870

Offset

1,1

Links

Table of n, a(n) for n=1..24.

Example

5389230 is in the sequence because it has 6 distinct prime factors (2, 3, 5, 7, 11 and 2333) and 2333 > sqrt(5389230).

Maple

with(numtheory): a:=proc(n) if nops(factorset(n))=6 and factorset(n)[6]^2>=n then n else fi end: seq(a(n), n=(2*3*5*7*11)^2..5850000);

Mathematica

dpf6Q[n_]:=Module[{pf=FactorInteger[n][[All, 1]]}, Length[pf]==6 && pf[[6]]>=Sqrt[n]]; Select[Range[6*10^6], dpf6Q] (* Harvey P. Dale, Mar 24 2017 *)

Crossrefs

Cf. A115956, A115957, A115958, A115959, A115961.

Sequence in context: A058252 A147528 A338542 * A186014 A234496 A022258

Adjacent sequences: A115957 A115958 A115959 * A115961 A115962 A115963

Keyword

nonn

Author

Emeric Deutsch, Feb 02 2006

Status

approved