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 A133014 #2 Mar 30 2012 17:33:49 %S A133014 3,731,1278191131071, %T A133014 52428721474836472305843009213693951618970019642690137449562111 %N A133014 Concatenation of next n Mersenne primes. %Y A133014 Cf. A053067, A053068. Mersenne primes: A000668. %K A133014 easy,nonn,base %O A133014 1,1 %A A133014 _Omar E. Pol_, Oct 19 2007