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 A120312 #24 Apr 29 2025 17:49:30
%S A120312 7,10,21,37,40,53,55,57,71,89,108,134,135,136,151,152,174,176,178,194,
%T A120312 196,223,226,263,264,265,267,268,312,337,338,339,341,342,343,345,359,
%U A120312 361,362,366,384,388
%N A120312 Numbers k such that pi(k) == 0 (mod 4), where pi() = A000720, and such that prime(k) == 1 (mod 4).
%H A120312 Harvey P. Dale, <a href="/A120312/b120312.txt">Table of n, a(n) for n = 1..1000</a>
%t A120312 a = Flatten[Table[If[Mod[PrimePi[n], 4] == 0&& Mod[Prime[n], 4] - 1 == 0, n, {}], {n, 1, 200}]]
%t A120312 Select[Range[400],Mod[PrimePi[#],4]==0&&Mod[Prime[#],4]==1&] (* _Harvey P. Dale_, Apr 29 2025 *)
%Y A120312 Cf. A000720. Intersection of A080147 and A120309.
%K A120312 nonn
%O A120312 1,1
%A A120312 _Roger L. Bagula_, Jun 20 2006
%E A120312 Edited and more terms added by _Michel Marcus_, Jun 01 2013
%E A120312 Offset corrected by _Michel Marcus_, Feb 10 2021