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 A209333 #9 Mar 30 2012 18:53:00 %S A209333 25,33,37,47,49,53,61,73,83,85,89,97,113,115,117,131,133,139,141,145, %T A209333 151,153,157,167,169,173,181,193,199,201,203,205,211,213,217,229,233, %U A209333 257,265,271,273,277,283,287,289,293,295,297,299,301,313,317 %N A209333 Numbers n for which A209332(n)=0. %Y A209333 Cf. A209332. %K A209333 nonn %O A209333 1,1 %A A209333 _Vladimir Shevelev_, Mar 06 2012