%I #17 May 11 2017 18:19:25
%S 121,253,793,1261,1441,1633,1837,2773,3601,3901,4213,4537,4873,5221,
%T 7141,9841,11881,14113,14701,16537,17173,17821,19153,19837,21241,
%U 22693,23437,24193,24961,28153,28981,29821,30673,34201,37921,38881,39853,40837,41833,43861,45937,48061,49141,50233,53581,55873
%N Centered 12-gonal numbers which are semiprimes, intersection of A003154 and A001358.
%C Might also be called 'semiprime star numbers'.
%C A083749 and A006061 are subsequences.
%H Zak Seidov, <a href="/A218172/b218172.txt">Table of n, a(n) for n = 1..1000</a>
%e a(1) = 121 = 11^2 = A001358(40) = A003154(5) = A083749(1) = A006061(1) = A078972(11).
%e a(2) = 253 = 11*23 = A001358(81) = A003154(7) = A083749(2) = A078972(18).
%t Select[Table[6n(n-1)+1,{n,100}],PrimeOmega[#]==2&] (* _Harvey P. Dale_, Sep 01 2014 *)
%o (PARI) lista(nn) = {for (n = 1, nn, if (bigomega(v = 6*n*(n-1) + 1) == 2, print1(v, ", ")););} \\ _Michel Marcus_, Nov 09 2013
%Y Cf. A003154, A001358, A006061, A078972, A083749.
%K nonn
%O 1,1
%A _Zak Seidov_, Oct 22 2012