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 A204806 #4 Mar 30 2012 17:23:05
%S A204806 142414669,229949449,257789053,258063709,260297563,268625899,
%T A204806 306099181,314919391,364008181,376789801,385240381,394059907,
%U A204806 401400211,425592157,439385917,458614501,470906101,486127723,496201099,497422531,499512049
%N A204806 Primes followed by a gap of 190 = nextprime(p)-p.
%H A204806 <a href="/index/Pri#gaps">Index entries for primes, gaps between</a>.
%o A204806 (PARI) list_gaps(g=190,f,N=100)={my(p=0); for(c=1, N, while(g+p!=p=nextprime(p+1), ); if(f,write(f".txt",c" ",p-g),print1(", "p-g)))}
%K A204806 nonn
%O A204806 1,1
%A A204806 _M. F. Hasler_, Jan 19 2012