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 A072947 #6 Oct 11 2013 20:32:17 %S A072947 2,191373251117,37291913732511172331, %T A072947 1391311131071018979716153433729191373251117233141475967738397103109127137149 %N A072947 Primes in A053065. %C A072947 The next term is too large to include. %Y A072947 Cf. A053065. %K A072947 nonn %O A072947 1,1 %A A072947 _Felice Russo_, Aug 20 2002