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 A210013 #10 Jun 10 2016 00:20:59 %S A210013 5631890724,6581324079,6581324097,7249056318 %N A210013 Pandigital numbers (A050278) with each product of three adjacent digits visible as a substring of the digits. %C A210013 Computed by Jean-Marc Falcoz. %H A210013 Eric Angelini, <a href="http://www.cetteadressecomportecinquantesignes.com/DixChiffres.htm">10 different digits, 9 products</a> %H A210013 E. Angelini, <a href="/A198298/a198298.pdf">10 different digits, 9 products</a> [Cached copy, with permission] %Y A210013 A generalization of A198298. Cf. A210013-A210020, A203569, A203566. %K A210013 nonn,base,fini,full %O A210013 1,1 %A A210013 _N. J. A. Sloane_, Mar 16 2012