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 A032665 #9 Sep 03 2017 03:20:56 %S A032665 3,9,11,23,27,29,33,39,41,51,57,63,69,71,77,81,83,93,111,113,129,131, %T A032665 137,141,143,153,161,179,203,207,213,221,237,239,243,251,267,269,273, %U A032665 281,287,293,297,309,311,333,339,341,347,351,357,371,377,381,383,389 %N A032665 Digit '2' concatenated with a(n) is a prime. %H A032665 Seiichi Manyama, <a href="/A032665/b032665.txt">Table of n, a(n) for n = 1..10000</a> %K A032665 nonn,base %O A032665 1,1 %A A032665 _Patrick De Geest_, May 15 1998