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 A143726 #16 May 26 2022 09:04:09
%S A143726 733,773,823,857,877,947,997,1033,1087,1123,1213,1223,1283,1307,1327,
%T A143726 1423,1487,1607,1993,2027,2137,2153,2237,2273,2287,2333,2543,2663,
%U A143726 2677,2693,2797,2803,2917,3187,3257,3323,3407,3433,3463,3467,3593,3623,3847
%N A143726 Middle members of beastly cousin prime triples: primes p such that both p+666 and p-666 are prime.
%H A143726 Felix Fröhlich, <a href="/A143726/b143726.txt">Table of n, a(n) for n = 1..10000</a>
%e A143726 733 - 666 = 67, 733 + 666 = 1399 and 67, 733, 1399 are all prime, so 733 is a term of the sequence. - _Felix Fröhlich_, May 26 2022
%t A143726 lst={};b=666;Do[p=Prime[n];If[PrimeQ[p+b]&&PrimeQ[p-b],AppendTo[lst,p]],{n,5!+2,7!}];lst
%t A143726 Select[Prime[Range[122,600]],AllTrue[#+{666,-666},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Apr 08 2018 *)
%o A143726 (PARI) forprime(p=1, 3900, if(ispseudoprime(p+666) && ispseudoprime(p-666), print1(p, ", "))) \\ _Felix Fröhlich_, May 26 2022
%Y A143726 Cf. A007529 (p, p+2 or +4, p+6 prime), A023200 (p and p+4 prime), A046132 (p-4 and p prime), A073648 (p-2, p and p+4 prime).
%K A143726 nonn
%O A143726 1,1
%A A143726 _Vladimir Joseph Stephan Orlovsky_, Aug 30 2008
%E A143726 Name edited by _Felix Fröhlich_, May 26 2022