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 A234498 #7 Nov 30 2016 23:06:05
%S A234498 1155,1995,3135,3255,3315,4935,5115,5187,6783,7035,7095,7215,7395,
%T A234498 7455,7755,8463,8547,8715,9867,10335,10455,10695,10815,11055,11715,
%U A234498 11739,12243,12903,14595,14835,15855,16107,16359,16779,16863,17043,17255,17355,18183
%N A234498 Products p*q*r*s of distinct primes for which (p*q*r*s - 1)/2 is prime.
%e A234498 1155 = 3*5*7*11 is the least product of 4 distinct primes p,q,r,s for which (p*q*r*s-1)/2 is a prime: 577.
%t A234498 t = Select[Range[1, 20000, 2], Map[Last, FactorInteger[#]] == Table[1, {4}] &]; Take[(t - 1)/2, 120] (* A234105 *)
%t A234498 v = Flatten[Position[PrimeQ[(t - 1)/2], True]] ; w = Table[t[[v[[n]]]], {n, 1, Length[v]}] (* A234498 *)
%t A234498 (w - 1)/2 (* A234499 *) (* _Peter J. C. Moses_, Dec 23 2013 *)
%Y A234498 Cf. A234105, A234499, A234500, A234097.
%K A234498 nonn,easy
%O A234498 1,1
%A A234498 _Clark Kimberling_, Jan 01 2014