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 A173468 #8 Sep 26 2016 20:52:46
%S A173468 3,15,121,1365,19531,335923,6725601,153391689,3922632451,111111111111,
%T A173468 3452271214393,116719860413533,4265491084507563,167534872139182395,
%U A173468 7037580381120954241,314824432191309680913,14942027230321957802947
%N A173468 Sum n^k, k=0..n+1.
%C A173468 1^0+1^1+1^2=3, 2^0+2^1+2^2+2^3=15, 3^0+3^1+3^2+3^3+3^4=121,..
%H A173468 Robert Israel, <a href="/A173468/b173468.txt">Table of n, a(n) for n = 1..385</a>
%F A173468 a(n) = (n^(n+2)-1)/(n-1) for n > 1. - _Robert Israel_, Sep 26 2016
%p A173468 3, seq((n^(n+2)-1)/(n-1),n=2..20); # _Robert Israel_, Sep 26 2016
%t A173468 f[n_]:=Module[{s=0},Do[s+=n^a,{a,0,n+1}];s]; lst={};Do[AppendTo[lst,f[n]],{n,30}];lst
%t A173468 Table[Sum[n^k,{k,0,n+1}],{n,20}] (* _Harvey P. Dale_, Jan 04 2012 *)
%Y A173468 Cf. A031973
%K A173468 nonn
%O A173468 1,1
%A A173468 _Vladimir Joseph Stephan Orlovsky_, Feb 18 2010