%I #7 Sep 13 2023 22:50:27
%S 1,3,7,9,13,19,21,27,31,37,39,43,49,57,61,63,67,73,79,81,91,93,97,103,
%T 109,111,117,127,129,133,139,147,151,157,163,169,171,181,183,189,193,
%U 199,201,211,217,219,223,229,237,241,243,247,259,271,273,277,279
%N Numbers not divisible by any prime of the form 3*k - 1.
%C The sequence is closed under multiplication.
%t s = Select[Prime[Range[100]], Mod[#, 3] == 2 &] (* A003627 *)
%t Select[r = Range[Max[s]], Intersection[#/s, r] == {} &]
%Y Cf. A003627, A364832.
%Y A215800 is a subsequence.
%K nonn
%O 1,2
%A _Clark Kimberling_, Aug 09 2023