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 A023221 #27 Sep 08 2022 08:44:47 %S A023221 2,3,7,11,13,17,29,31,37,41,43,59,71,73,79,83,97,107,109,113,137,139, %T A023221 151,157,163,181,191,193,197,227,239,241,251,263,269,277,307,311,317, %U A023221 337,347,349,367,373,389,401,409,421,431,443,449,479,487,499,503,541,557,577,587 %N A023221 Primes p such that 6*p + 5 is also prime. %H A023221 Vincenzo Librandi, <a href="/A023221/b023221.txt">Table of n, a(n) for n = 1..1000</a> %t A023221 Select[Prime[Range[1000]], PrimeQ[6 # + 5] &] (* _Vincenzo Librandi_, May 20 2014 *) %o A023221 (Magma) [n: n in PrimesUpTo(100) | IsPrime(6*n+5)]; // _Vincenzo Librandi_, Nov 20 2010 %Y A023221 Subsequence of A059325. %K A023221 nonn,easy %O A023221 1,1 %A A023221 _David W. Wilson_