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 A229908 #24 Oct 19 2014 15:57:16 %S A229908 2,13,13,37,113,113,137,1237,1373,1733,1733,11317,11731,12713,19973, %T A229908 91733,113173,113371,113371,173347,991733,1123379,1134673,1137991, %U A229908 1237199,2333719,7433719,11133719,11399173,11399173,11791733,37914713,97433719,113217397,113217397,113337199,113337199,113337199,1113371999,1113371999,1113991733,1139917321,1139917321,1139917333 %N A229908 The least prime that has at least n embedded primes, reading forward and backward. %C A229908 Results of my search up to 2^32. %H A229908 Giovanni Resta, <a href="/A229908/b229908.txt">Table of n, a(n) for n = 1..65</a> (terms < 3.5*10^12) %H A229908 C. Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_724.htm">Puzzle 724. Extending the OEIS sequence A229908</a> %e A229908 Example: a(8) = 1237 because there are the following eight embedded primes: 1237, 2, 23, 3, 37, 7 and 73, 7321. %Y A229908 Cf. A039993, A039997. %K A229908 nonn,base,hard %O A229908 1,1 %A A229908 _Carlos Rivera_, Dec 19 2013 %E A229908 Missing a(19) from _Giovanni Resta_, Jan 25 2014