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 A068693 #8 May 02 2016 11:04:18 %S A068693 3,11,113,1117,11113,111119,1111151,11111117,111111113,1111111139, %T A068693 11111111113,111111111337,1111111111139,11111111111533, %U A068693 111111111111713,1111111111111153,11111111111111119,111111111111111131,1111111111111111111,11111111111111111131 %N A068693 Smallest n-digit prime with all odd digits. %H A068693 Alois P. Heinz, <a href="/A068693/b068693.txt">Table of n, a(n) for n = 1..500</a> %Y A068693 Cf. A068690, A068691, A068692. %K A068693 base,nonn %O A068693 1,1 %A A068693 _Amarnath Murthy_, Mar 03 2002 %E A068693 More terms from _Sascha Kurz_, Mar 17 2002