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 A139440 #15 Dec 29 2016 02:33:40
%S A139440 3,4,5,7,12,15,26,31,50,71,186,273,366,1542,1929,3687,4407,15395,15433
%N A139440 Numbers n such that primorial(n)/2 - 4 is prime.
%C A139440 a(20) > 25000. - _Robert Price_, Dec 03 2016
%t A139440 k = 1; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k - 4], Print[n]; AppendTo[a, n]], {n, 2, 366}]; a
%Y A139440 Cf. A067026, A067027, A139439-A139457, A103514.
%K A139440 nonn
%O A139440 1,1
%A A139440 _Artur Jasinski_, Apr 21 2008
%E A139440 a(14)-a(15) from _Ray Chandler_, Jun 16 2013
%E A139440 a(16)-a(17) from _Robert Price_, Aug 16 2016
%E A139440 a(18) from _Robert Price_, Dec 03 2016
%E A139440 Added missing term, 15395 by _Robert Price_, Dec 28 2016