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A046390 Squarefree odd numbers with exactly 4 distinct prime factors. 3
1155, 1365, 1785, 1995, 2145, 2415, 2805, 3003, 3045, 3135, 3255, 3315, 3705, 3795, 3885, 3927, 4305, 4389, 4485, 4515, 4641, 4785, 4845, 4935, 5005, 5115, 5187, 5313, 5565, 5655, 5865, 6045, 6105, 6195, 6279, 6405, 6545, 6555, 6699, 6765, 6783, 7035 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

f[n_]:=Last/@FactorInteger[n]=={1, 1, 1, 1}&&FactorInteger[n][[1, 1]]>2; lst={}; Do[If[f[n], AppendTo[lst, n]], {n, 8!}]; lst (* Vladimir Joseph Stephan Orlovsky, Nov 23 2009 *)

Select[Range[1, 8001, 2], PrimeNu[#]==PrimeOmega[#]==4&] (* Harvey P. Dale, Mar 28 2013 *)

CROSSREFS

Cf. A046317, A046406.

Sequence in context: A107557 A020382 A185689 * A234498 A147577 A211133

Adjacent sequences:  A046387 A046388 A046389 * A046391 A046392 A046393

KEYWORD

nonn

AUTHOR

Patrick De Geest, Jun 15 1998

STATUS

approved

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Last modified February 23 08:18 EST 2019. Contains 320420 sequences. (Running on oeis4.)