cp's OEIS Frontend

A046337 Odd numbers with an even number of prime factors (counted with multiplicity).

%I A046337 #36 Feb 05 2024 18:08:26
%S A046337 1,9,15,21,25,33,35,39,49,51,55,57,65,69,77,81,85,87,91,93,95,111,115,
%T A046337 119,121,123,129,133,135,141,143,145,155,159,161,169,177,183,185,187,
%U A046337 189,201,203,205,209,213,215,217,219,221,225,235,237,247,249,253,259
%N A046337 Odd numbers with an even number of prime factors (counted with multiplicity).
%H A046337 John Cerkan, <a href="/A046337/b046337.txt">Table of n, a(n) for n = 1..10000</a>
%F A046337 {k | A000035(k) > 0 and A008836(k) > 0}. - _Antti Karttunen_, Jan 13 2023
%t A046337 Select[Range[1,301,2],EvenQ[PrimeOmega[#]]&] (* _Harvey P. Dale_, Jul 25 2011 *)
%o A046337 (PARI) lista(nn) = {forstep(n=1, nn, 2, if (bigomega(n) % 2 == 0, print1(n, ", ")));} \\ _Michel Marcus_, Jul 04 2015
%Y A046337 Intersection of A005408 and A028260.
%Y A046337 Setwise difference A005408 \ A067019.
%Y A046337 Setwise difference A028260 \ A063745.
%Y A046337 Union of A359161 and A359163.
%Y A046337 Union of A327862 and A360110.
%Y A046337 Subsequence of A345452, of A356312 and of A359371.
%Y A046337 Positions of positive terms in A166698, positions of even terms in A327858 and A356299.
%Y A046337 Subsequences: A002557, A046315 (odd semiprimes), A056913, A359596, A359607, A359608 (without its term 2).
%Y A046337 Cf. A000035, A008836, A046338, A046470, A353557 (characteristic function), A358777.
%Y A046337 Cf. also A036349, A297845.
%K A046337 nonn
%O A046337 1,2
%A A046337 _Patrick De Geest_, Jun 15 1998