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 A024902 #21 Sep 08 2022 08:44:48 %S A024902 1,7,9,15,19,21,25,27,37,39,49,55,61,69,79,81,85,87,91,97,105,115,117, %T A024902 129,139,141,145,147,151,157,159,169,171,175,189,205,207,211,217,225, %U A024902 229,231,237,247,249,255,261,267,271,285,289,295,297,301,307,319,321,327,339,349 %N A024902 Numbers k such that 7*k + 4 is prime. %H A024902 Vincenzo Librandi, <a href="/A024902/b024902.txt">Table of n, a(n) for n = 1..1000</a> %t A024902 Select[Range[400], PrimeQ[7 # + 4] &] (* _Vincenzo Librandi_, Sep 26 2012 *) %o A024902 (Magma) [n: n in [1..400] | IsPrime(7*n+4)]; // _Vincenzo Librandi_, Nov 20 2010 %o A024902 (PARI) is(n)=isprime(7*n+4) \\ _Charles R Greathouse IV_, Feb 20 2017 %Y A024902 Cf. A045471 (associated primes). %K A024902 nonn,easy %O A024902 1,2 %A A024902 _Clark Kimberling_