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 A051813 #4 Jun 11 2014 17:24:22
%S A051813 1,15,208,2389,24845,243697,2348885,22837227,226507501,2285904554,
%T A051813 23239957877,235731610792,2372897841904,23686630752065,
%U A051813 235058927877399,2327977363798607
%N A051813 Number of n-digit numbers with nonzero multiplicative digital root 2.
%D A051813 William Mayne, sci.math, Jun 15 1991
%F A051813 # { i : 10^(n-1) < i < 10^n and A051802(i)=2 }
%Y A051813 Cf. A051802, A051804, A051822.
%K A051813 nonn,base,hard
%O A051813 1,2
%A A051813 _Dan Hoey_, Dec 09 1999