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 A014888 #5 Mar 30 2012 17:28:13 %S A014888 761729,761730,823543,1585272,1585273,1647086,2408815,2408816,2470629, %T A014888 3232358,3232359 %N A014888 n is equal to the number of 4s in all numbers <= n written in base 7. %Y A014888 Cf. A014778, A014886. %K A014888 nonn,base,fini,full %O A014888 1,1 %A A014888 _Olivier Gérard_ %E A014888 List proved complete by _Hugo van der Sanden_ (cf. A014886).