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 A030161 #8 Feb 12 2021 17:48:11 %S A030161 0,1,2,3,5,6,7,9,18,23,85,87,101,103,301,303,363,725 %N A030161 Numbers k such that in k and k^3 the parity of digits alternates. %C A030161 No other values of k < 2100000. - Larry Reeves (larryr(AT)acm.org), Sep 25 2000 %Y A030161 Cf. A030162. %K A030161 nonn,base %O A030161 1,3 %A A030161 _Patrick De Geest_