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 A339594 #3 Jan 02 2021 11:51:18 %S A339594 0,4,9,12,25,9,49,16,27,25,121,13,169 %N A339594 Two-dimensional Kempner (or Kempner-Smarandache) numbers. %H A339594 Norbert Hungerbühler, Ernst Specker, <a href="http://www.emis.de/journals/INTEGERS/papers/g23/g23.Abstract.html">A generalization of the Smarandache Function to several variables</a>, INTEGERS 6 (2006) #A23 %Y A339594 Cf. A002034, A339595, A339596. %K A339594 nonn,more %O A339594 1,2 %A A339594 _N. J. A. Sloane_, Jan 02 2021