A120312 - OEIS

%I #19 Feb 10 2021 03:29:44

%S 7,10,21,37,40,53,55,57,71,89,108,134,135,136,151,152,174,176,178,194,

%T 196,223,226,263,264,265,267,268,312,337,338,339,341,342,343,345,359,

%U 361,362,366,384,388

%N Numbers k such that pi(k) == 0 (mod 4), where pi() = A000720, and such that prime(k) == 1 (mod 4).

%t a = Flatten[Table[If[Mod[PrimePi[n], 4] == 0&& Mod[Prime[n], 4] - 1 == 0, n, {}], {n, 1, 200}]]

%Y Cf. A000720. Intersection of A080147 and A120309.

%K nonn

%O 1,1

%A _Roger L. Bagula_, Jun 20 2006

%E Edited and more terms added by _Michel Marcus_, Jun 01 2013

%E Offset corrected by _Michel Marcus_, Feb 10 2021