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 A032687 #9 Jul 28 2021 04:24:05 %S A032687 0,9,12,13,15,16,18,21,22,24,31,36,40,43,45,60,61,63,66,75,76,79,84, %T A032687 87,94,100,103,109,114,126,129,130,136,138,145,157,163,171,172,177, %U A032687 186,189,190,195,201,205,213,217,222,237,240,243,253,256,259 %N A032687 Numbers k such that k surrounded by digit '3' is a lucky number. %Y A032687 Cf. A000959, A032683. %K A032687 nonn,base %O A032687 1,2 %A A032687 _Patrick De Geest_, May 15 1998