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 A051824 #4 Jun 11 2014 17:24:23
%S A051824 1,13,118,898,6350,46329,382410,3645765,38163792,410943130,4368127170,
%T A051824 45097983418,451960864264,4431128837948,42987600398290,417247179973351
%N A051824 Number of numbers below 10^n with nonzero multiplicative digital root 4.
%D A051824 William Mayne, sci.math, Jun 15 1991
%F A051824 # { i : 10^(n-1) < i < 10^n and A051802(i)=4 }
%Y A051824 Cf. A051802, A051806, A051815.
%K A051824 nonn,base,hard
%O A051824 1,2
%A A051824 _Dan Hoey_, Dec 09 1999