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 A117667 #24 Apr 20 2015 21:02:28
%S A117667 1,2,15,172,2345,37326,686287,14380472,338992929,8888888890,
%T A117667 256780503551,8105545862052,277635514376233,10257237069745862,
%U A117667 406615755353655135,17216961135462248176,775537745518440716417
%N A117667 a(n) = n^n-n^(n-1)-n^(n-2)-n^(n-3)-...-n^3-n^2-n.
%H A117667 Christian N. K. Anderson, <a href="/A117667/b117667.txt">Table of n, a(n) for n = 1..100</a>
%F A117667 a(n) = A000312(n) - A023037(n) + 1. - _Michel Marcus_, Apr 14 2015
%F A117667 A191690(n)+1. - _Robert G. Wilson v_, Apr 16 2015
%e A117667 a(3) = 3^3-3^2-3 = 27-9-3 = 15.
%p A117667 a:=n->n^n-sum(n^j,j=1..n-1): seq(a(n),n=1..19); # _Emeric Deutsch_, Apr 16 2006
%t A117667 s[n_] := Sum[n^i, {i, 1, n - 1}]; Table[n^n - s[n], {n, 17}] (* _Carlos Eduardo Olivieri_, Apr 14 2015 *)
%t A117667 f[n_] := ((n - 2) n^n + n)/(n - 1); f[1] = 1; Array[f, 18] (* _Robert G. Wilson v_, Apr 15 2015 *)
%Y A117667 Cf. A000312 (n^n), A023037 (1+n+n^2+...n^(n-1)),
%Y A117667 A001923, A031972.
%K A117667 nonn
%O A117667 1,2
%A A117667 Luc Stevens (lms022(AT)yahoo.com), Apr 11 2006