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 A139449 #11 Apr 11 2017 04:37:17
%S A139449 2,4,5,7,8,10,11,23,25,67,87,125,141,242,255,258,279,316,449,578,871,
%T A139449 1072,1886,2071,3315,18225
%N A139449 Numbers n such that primorial(n)/2 + 128 is prime.
%C A139449 a(27) > 25000. - _Robert Price_, Apr 10 2017
%t A139449 k = 1/2; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k + 128], Print[n]; AppendTo[a, n]], {n, 325}]; a
%t A139449 Select[Range[0, 25000], PrimeQ[Product[Prime[k], {k, 1, #}]/2 + 128] &] (* _Robert Price_, Apr 10 2017 *)
%Y A139449 Cf. A067026, A067027, A139439-A139457, A103514.
%K A139449 nonn
%O A139449 1,1
%A A139449 _Artur Jasinski_, Apr 21 2008
%E A139449 a(18)-a(24) from _Ray Chandler_, Jun 16 2013
%E A139449 a(25)-a(26) from _Robert Price_, Apr 10 2017