This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A067019 #26 Feb 15 2025 18:21:21
%S A067019 3,5,7,11,13,17,19,23,27,29,31,37,41,43,45,47,53,59,61,63,67,71,73,75,
%T A067019 79,83,89,97,99,101,103,105,107,109,113,117,125,127,131,137,139,147,
%U A067019 149,151,153,157,163,165,167,171,173,175,179,181,191,193,195,197,199
%N A067019 Odd numbers with an odd number of prime factors (counted with multiplicity).
%C A067019 Subsequence of odd terms of A026424. - _Michel Marcus_, Jul 04 2015
%C A067019 The sequence a(1)=0, for n>1 a(n) is smallest number such that for all s,t,m<n a(n) != a(s)*a(t)+a(m) is the same as this one from a(3). - _Anders Hellström_, Jul 08 2015
%H A067019 Harry J. Smith, <a href="/A067019/b067019.txt">Table of n, a(n) for n = 1..1000</a>
%e A067019 a(9) = 27, which is odd with an odd number of prime factors, i.e., 3.
%t A067019 Select[Range[1,301,2],OddQ[PrimeOmega[#]]&] (* _Harvey P. Dale_, Feb 15 2025 *)
%o A067019 (PARI) isok(k) = { k%2 == 1 && bigomega(k)%2 == 1 } \\ _Harry J. Smith_, Apr 25 2010
%Y A067019 Intersection of A005408 and A026424.
%Y A067019 Setwise difference A005408 \ A046337.
%Y A067019 Cf. A353558 (characteristic function).
%Y A067019 Positions of the terms of the form 4u+2 (A016825) in A358669 (and in A358765).
%K A067019 nonn
%O A067019 1,1
%A A067019 _Shyam Sunder Gupta_, Feb 16 2002