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 A089573 #3 Mar 30 2012 17:29:13 %S A089573 19,419,5419,35419,735419,9735419,159735419,14159735419,114159735419, %T A089573 60114159735419,2660114159735419,282660114159735419, %U A089573 6282660114159735419,206282660114159735419,13206282660114159735419 %N A089573 Primes arising in A089572. %Y A089573 Cf. A089710, A089711, A089560-A089572. %K A089573 base,nonn %O A089573 1,1 %A A089573 _Ray Chandler_, Nov 22 2003