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 A234502 #10 Jun 24 2015 04:21:53
%S A234502 683,1523,2153,2243,2393,2423,2503,2657,3023,3203,3581,3833,4133,4373,
%T A234502 4583,4673,4967,5003,5051,5233,5273,5303,5483,5653,5843,6221,6299,
%U A234502 6793,7193,7211,7487,7523,7703,7823,7937,8093,8243,8543,8693,9323,9377,9461,9533
%N A234502 Primes of the form (p*q*r*s + 1)/2, where p, q, r, s are distinct primes.
%e A234502 (See A234501.)
%t A234502 t = Select[Range[1, 20000, 2], Map[Last, FactorInteger[#]] == Table[1, {4}] &]; Take[(t + 1)/2, 120] (* A234500 *)
%t A234502 v = Flatten[Position[PrimeQ[(t + 1)/2], True]] ; w = Table[t[[v[[n]]]], {n, 1, Length[v]}] (* A234501 *)
%t A234502 (w + 1)/2 (* A234502 *) (* _Peter J. C. Moses_, Dec 23 2013 *)
%Y A234502 Cf. A234500, A234501, A234499, A234104.
%K A234502 nonn,easy
%O A234502 1,1
%A A234502 _Clark Kimberling_, Jan 01 2014