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 A163603 #16 Mar 01 2021 07:02:55 %S A163603 3,8,15,18,24,27,32,40,50,55,58,65,76,78,85,91,97,99,108,111,123,125, %T A163603 128,130,135,149,154,158,164,170,180,184,191,194,200,203,207,214,216, %U A163603 227,229,237,242,246,252,260,266,271 %N A163603 Numbers k such that prime(k) == 5 (mod 7). %C A163603 The asymptotic density of this sequence is 1/6 (by Dirichlet's theorem). - _Amiram Eldar_, Mar 01 2021 %H A163603 G. C. Greubel, <a href="/A163603/b163603.txt">Table of n, a(n) for n = 1..5000</a> %F A163603 a(n) = A000720(A045458(n)). %F A163603 A000040(a(n)) = A045458(n). %t A163603 Select[Range[300], Mod[Prime[#], 7] == 5 &] (* _G. C. Greubel_, Jul 29 2017 *) %o A163603 (PARI) isok(n) = (prime(n) % 7) == 5; \\ _Michel Marcus_, Jul 29 2017 %Y A163603 Cf. A000040, A000720, A045458. %K A163603 nonn %O A163603 1,1 %A A163603 _Juri-Stepan Gerasimov_, Aug 01 2009 %E A163603 Remainder in definition corrected by _R. J. Mathar_, Aug 01 2009