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 A156592 #20 Feb 10 2015 04:03:20
%S A156592 10,21,55,253,1081,1711,3403,5671,13861,15931,25651,34453,60031,64261,
%T A156592 73153,108811,114481,126253,158203,171991,258121,351541,371953,392941,
%U A156592 482653,518671,703891,822403,853471,869221,933661,1034641,1104841
%N A156592 Product p*q of two primes with q = 2*p + 1.
%C A156592 Subsequence of A068443.
%C A156592 Products of Sophie Germain primes p with their corresponding safe primes 2p+1. The smallest prime factor of a(n) is (a(n) - phi(a(n)))/3 and the largest prime factor of a(n) is 2(a(n) - phi(a(n)))/3 + 1. - _Wesley Ivan Hurt_, Oct 03 2013
%H A156592 Vincenzo Librandi, <a href="/A156592/b156592.txt">Table of n, a(n) for n = 1..4000</a>
%H A156592 <a href="http://dxdy.ru/topic16349.html">Math Marathon (MM95)</a> (in Russian) [from Vladimir Joseph Stephan Orlovsky, May 12 2010]
%F A156592 a(n) = A005384(n)*A005385(n).
%t A156592 lst={};Do[p=Prime[n];q=2*p+1;If[PrimeQ[q],AppendTo[lst,p*q]],{n,5!}];lst (* _Vladimir Joseph Stephan Orlovsky_, May 12 2010 *)
%Y A156592 Cf. A005384, A005385. Subset of A001358.
%K A156592 nonn
%O A156592 1,1
%A A156592 _Reinhard Zumkeller_, Feb 10 2009