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 A139407 #11 Mar 19 2020 06:53:46
%S A139407 2,5,8,20,38,47,62,80,92,107,110,113,185,197,233,260,275,293,317,332,
%T A139407 335,338,377,395,398,488,500,653,668,722,740,755,818,863,905,950,962,
%U A139407 965,1052,1055,1067,1097,1100,1193,1202,1217,1223,1235,1262,1280,1283
%N A139407 Numbers k such that 8*k+3 and 8*k+7 are primes.
%H A139407 Amiram Eldar, <a href="/A139407/b139407.txt">Table of n, a(n) for n = 1..10000</a>
%t A139407 a = {}; Do[If[PrimeQ[8 n + 3] && PrimeQ[8 n + 7], AppendTo[a, n]], {n, 1, 1000}]; a
%t A139407 Select[Range[1500],And@@PrimeQ[8 # +{3,7}]&] (* _Harvey P. Dale_, Mar 24 2011 *)
%Y A139407 Cf. A125821, A125822, A139402, A139404, A139405, A139406.
%K A139407 nonn
%O A139407 1,1
%A A139407 _Artur Jasinski_, Apr 19 2008