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 A204672 #22 Dec 16 2017 23:27:00
%S A204672 1895359,2898239,6085441,7160227,7784039,7803491,7826899,8367397,
%T A204672 8648557,9452959,10052071,10863973,11630503,11962823,12109697,
%U A204672 12230233,12415681,14411737,14531899,15014557,15020737,15611909,16179041
%N A204672 Primes followed by a gap of 120.
%H A204672 M. F. Hasler, <a href="/A204672/b204672.txt">Table of n, a(n) for n = 1..433</a> (all a(n) < 10^8).
%H A204672 <a href="/index/Pri#gaps">Index entries for primes, gaps between</a>
%t A204672 Transpose[Select[Partition[Prime[Range[1100000]],2,1],Last[#]-First[#] == 120&]] [[1]] (* _Harvey P. Dale_, Jul 11 2014 *)
%o A204672 (PARI) g=120;c=o=0;forprime(p=1,default(primelimit),(-o+o=p)==g&write("c:/temp/b204672.txt",c++" "p-g))
%o A204672 (MATLAB)
%o A204672 N = 2*10^7; % to get all terms <= N
%o A204672 P = primes(N+120);
%o A204672 J = find(P(2:end) - P(1:end-1) == 120);
%o A204672 P(J) % _Robert Israel_, Feb 28 2017
%Y A204672 Cf. A058193 (first gap of 6n), A140791 (first gap of 10n).
%Y A204672 Cf. A126771 (gap 60), A126724 (gap 150), A204673 (gap 180).
%Y A204672 Cf. A001359, A029710, A031924-A031938, A061779, A098974, A124594-A124596, A126784, A134116-A134124, A204665-A204670.
%K A204672 nonn
%O A204672 1,1
%A A204672 _M. F. Hasler_, Jan 18 2012