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 A247590 #11 Oct 07 2014 13:01:47
%S A247590 7,11,23,131,157,193,227,271,331,571,947,977,1013,1087,1283,1453,1657,
%T A247590 1871,2341,2671,2693,3607,3637,3691,4013,4951,5407,5653,6211,6353,
%U A247590 6653,6827,6977,6991,7541,7717,8053,8081,8537,9203,9613,9643,10853,11113,11251,11933
%N A247590 Primes p such that p + 6^k is also prime at least for k = 1, 2, 3 and 4.
%H A247590 K. D. Bajpai, <a href="/A247590/b247590.txt">Table of n, a(n) for n = 1..12638</a>
%e A247590 a(1) = 7 is prime. 7 + 6^1 = 13, 7 + 6^2 = 43, 7 + 6^3 = 223 and 7 + 6^4 = 1303 are also prime. It is the smallest such set of 5 primes; (Quintet).
%t A247590 Select[k = {1, 2, 3, 4}; Prime[Range[500]], And @@ PrimeQ[# + 6^k] &]
%o A247590 (PARI)
%o A247590 forprime(p=1,10^4,c=1;for(k=1,4,if(!isprime(p+6^k),c--;break));if(c,print1(p,", "))) \\ _Derek Orr_, Sep 20 2014
%Y A247590 Cf. A000040, A049494, A049495.
%K A247590 nonn,easy
%O A247590 1,1
%A A247590 _K. D. Bajpai_, Sep 20 2014