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 A139463 #11 Sep 27 2017 16:09:07
%S A139463 3,4,6,10,15,42,49,56,63,106,170,182,246,255,507,627,848,864,961,1302,
%T A139463 3209,4994,7665,7671,16405
%N A139463 Numbers n such that (product of the first n odd primes) - 2*prime(n+2) is a prime.
%C A139463 a(26) > 25000. - _Robert Price_, Sep 27 2017
%e A139463 3 is in the sequence because 3*5*7 - 2*11 = 83 is a prime.
%t A139463 k = 1; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k - 2*Prime[n + 1]], AppendTo[a, n - 1]], {n, 2, 2000}]; a
%o A139463 (PARI) isok(n) = isprime(prod(k=2, n+1, prime(k)) - 2*prime(n+2)); \\ _Michel Marcus_, Sep 27 2017
%Y A139463 Cf. A067026, A067027, A139439, A139440, A139441, A139442, A139443, A139444, A139445, A139446, A139447, A139448, A139449, A139450, A139451, A139452, A139453, A139454, A139455, A139456, A139457, A103514, A139460, A139461, A139462.
%K A139463 nonn,more
%O A139463 1,1
%A A139463 _Artur Jasinski_, Apr 22 2008
%E A139463 Edited by _Jens Kruse Andersen_, May 03 2008
%E A139463 a(15)-a(25) from _Robert Price_, Sep 27 2017