The OEIS is supported by the many generous donors to the OEIS Foundation.
%I #5 Jan 28 2013 12:02:14
%S 3,37,37,61,61,61,71,89,89,107,113,139,139,181,199,223,227,227,269,
%T 283,293,313,313,331,347,347,349,373,373,379,401,433,433,487,487,487,
%U 503,521,521,523,557,569,569,593,647,653,653,743,757,761,773,787,797,809
%N Primes of the form n-th semiprime-n.
%C Generated by indices n = 1, 20, 21, 32,.. shown in A176241. [From _R. J. Mathar_, Apr 13 2010]
%H Harvey P. Dale, <a href="/A176240/b176240.txt">Table of n, a(n) for n = 1..1000</a>
%e a(1)=3 because A001358(1)-1=4-1=3=prime.
%t Select[First[#]-Last[#]&/@Module[{sp=Select[Range[3000], PrimeOmega[#] == 2&], len}, len=Length[sp];Thread[{sp,Range[len]}]],PrimeQ] (* _Harvey P. Dale_, Jan 28 2013 *)
%K nonn
%O 1,1
%A _Juri-Stepan Gerasimov_, Apr 12 2010
%E More terms from _R. J. Mathar_, Apr 13 2010