%I #13 Aug 09 2014 23:07:16

%S 4,6,9,14,21,22,26,34,39,46,49,51,57,62,69,74,77,82,86,87,91,94,106,

%T 111,119,121,122,129,134,141,142,146,159,161,166,169,177,187,194,201,

%U 202,206,209,214,217,219,221,226,237,247,249,254,259,262,267,274,287,289

%N Semiprimes congruent to {1, 2, 4} mod 5.

%C Semiprimes in A032793.

%H K. D. Bajpai, <a href="/A241013/b241013.txt">Table of n, a(n) for n = 1..11280</a>

%e 21 = 3 * 7 which is semiprime and 21 = 1 mod 5.

%e 39 = 3 * 13 which is semiprime and 39 = 4 mod 5.

%t Select[Range[500], PrimeOmega[#] == 2 && MemberQ[{1, 2, 4}, Mod[#, 5]] &](* Bajpai *)

%t Select[Complement[Range[100], 5Range[20] - 2, 5Range[20]], PrimeOmega[#] == 2 &] (* _Alonso del Arte_, Aug 07 2014 *)

%o (PARI)

%o for(n=1,10^4,if(n!=Mod(0,5)&&n!=Mod(3,5),if(bigomega(n)==2,print1(n,", ")))) \\ _Derek Orr_, Aug 07 2014

%Y Cf. A001358, A032793, A045371.

%K nonn,easy

%O 1,1

%A _K. D. Bajpai_, Aug 07 2014