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 A272021 #20 Nov 07 2016 00:03:28
%S A272021 12012743,12147463,13408397,15303667,32676733,34460407,36050293,
%T A272021 36685867,36804487,37657423,41516063,51146867,54702367,56379217,
%U A272021 57203687,58250207,60696803,63699127,73576067,74663377,76853827,78725443,82015313,92438317,94073923,94988423
%N A272021 Balanced primes separated from the next lower and next higher prime neighbors by 66.
%C A272021 This was generated by calculating the first million primes in a spreadsheet, finding their differences and then looking for two consecutive differences equal to 66.
%H A272021 Giovanni Resta, <a href="/A272021/b272021.txt">Table of n, a(n) for n = 1..10000</a>
%t A272021 Prime[Last /@ SequencePosition[ Differences@ Prime@ Range[4 *10^6], {66, 66}]] (* _Giovanni Resta_, Apr 18 2016 *)
%o A272021 (PARI) list(lim)=my(v=List(),p=2,q=3); forprime(r=5,nextprime(lim+1), if(q-p==66 && r-q==66, listput(v,q)); p=q;q=r); Vec(v) \\ _Charles R Greathouse IV_, Apr 18 2016
%Y A272021 Cf. A054342, A058867, A178136.
%K A272021 nonn
%O A272021 1,1
%A A272021 _Wendy Appleby_, Apr 18 2016
%E A272021 a(5)-a(26) from _Giovanni Resta_, Apr 18 2016