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 A049494 #9 Jan 22 2018 21:09:20
%S A049494 7,37,163,757,967,1303,2293,2377,8677,8803,9157,9277,14827,15667,
%T A049494 16417,20113,27763,29863,41953,53593,56527,56893,61027,67153,69763,
%U A049494 74827,79333,83203,90007,95467,111577,129277,135193,137383,142543,151783
%N A049494 a(n) and a(n)+4^k are primes at least for k=1,2,3,4.
%H A049494 Harvey P. Dale, <a href="/A049494/b049494.txt">Table of n, a(n) for n = 1..1000</a>
%e A049494 7,7+4=11,7+16=23,7+64=71,7+256=263 are all primes: it is the smallest such quintet.
%t A049494 Select[Prime[Range[15000]],AllTrue[#+{4,16,64,256},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Jan 22 2018 *)
%o A049494 (PARI) isok(n) = isprime(n) && isprime(n+4) && isprime(n+4^2) && isprime(n+4^3) && isprime(n+4^4); \\ _Michel Marcus_, Dec 31 2013
%Y A049494 Cf. A023200, A049492, A049493, A049495-A049500.
%K A049494 nonn
%O A049494 1,1
%A A049494 _Labos Elemer_