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 A204816 #12 May 13 2013 01:50:02
%S A204816 1,1,4,3,4,5,1,1,4,3,4,5,4,1,4,3,4,5,3,1,4,3,4,5,4,1,4,3,4,5,1,1,4,3,
%T A204816 4,5,1,1,4,3,4,5,1,1,4,3,4,5,4,1,4,3,4,5,3,1,4,3,4,5,4,1,4,3,4,5,1,1,
%U A204816 4,3,4,5,4,1,4,3,4,5,1,1,4,3,4,5,4
%N A204816 Final nonzero digit of n^n in base 6.
%t A204816 f[0]=1;f[n_]:=Module[{m=n^n},While[Mod[m,6]==0,m=m/6];Mod[m,6]];Table[f[i],{i,0,100}]
%o A204816 (PARI) a(n)=lift(Mod(n/6^valuation(n,6),6)^n) \\ _Charles R Greathouse IV_, Jan 23 2012
%K A204816 nonn,easy,base
%O A204816 0,3
%A A204816 _José María Grau Ribas_, Jan 19 2012