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 A204817 #12 May 13 2013 01:50:02
%S A204817 1,1,4,6,4,3,1,1,1,1,4,2,1,6,4,1,2,5,1,5,1,6,1,4,1,4,4,6,4,1,1,3,2,6,
%T A204817 1,3,1,2,2,1,2,6,1,1,4,6,4,3,1,1,1,1,4,2,1,6,1,1,2,5,1,5,1,1,1,4,1,4,
%U A204817 4,6,4,1,1,3,2,6,1,2,1,2,2,1,2,6,1
%N A204817 Final nonzero digit of n^n in base 7.
%t A204817 f[0]=1;f[n_]:=Module[{m=n^n},While[Mod[m,7]==0,m=m/7];Mod[m,7]];Table[f[i],{i,0,100}]
%o A204817 (PARI) a(n)=lift(Mod(n/7^valuation(n,7),7)^n) \\ _Charles R Greathouse IV_, Jan 23 2012
%K A204817 nonn,easy,base
%O A204817 0,3
%A A204817 _José María Grau Ribas_, Jan 19 2012