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 A135219 #3 Mar 31 2012 10:22:05 %S A135219 99,949,9798,62498,997998,6244998 %N A135219 a(n) = largest number with n+1 digits and without zero digits whose squares have maximal number of zero digits = A135215(n+1). %Y A135219 Cf. A134843, A134844, A134845, A134846, A134847, A134848, A134849, A135215, A135216, A135217. %K A135219 nonn,base %O A135219 2,1 %A A135219 _Artur Jasinski_, Nov 23 2007