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 A089569 #3 Mar 30 2012 17:29:13 %S A089569 13,113,2113,192113,3192113,83192113,1583192113,181583192113, %T A089569 10181583192113,1710181583192113,451710181583192113, %U A089569 24451710181583192113,2224451710181583192113,112224451710181583192113 %N A089569 Primes arising in A089568. %Y A089569 Cf. A089710, A089711, A089560-A089573. %K A089569 base,nonn %O A089569 1,1 %A A089569 _Ray Chandler_, Nov 22 2003