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 A126778 #9 Dec 24 2012 02:05:48
%S A126778 2,12,110,1320,19502,341796,6927230,159338640,4100173022,116692730220,
%T A126778 3639243694814,123411407978040,4521172518708302,177943592279325684,
%U A126778 7487880700093141502,335470576863324471840,15942605654030732807102,801021400634789561255868
%N A126778 Number of functions f:{1,2,...,n}->{1,2,...,n} such that Im(f) contain two fixed elements.
%H A126778 Milan Janjic, <a href="http://www.pmfbl.org/janjic/">Enumerative Formulas for Some Functions on Finite Sets</a>
%F A126778 a(n)=n^n-2*(n-1)^n+(n-2)^n (n=2,3,...)
%p A126778 a:=n->n^n-2*(n-1)^n+(n-2)^n;
%t A126778 Drop[Table[Sum[(-1)^k Binomial[2,k] (n-k)^n,{k,0,2}],{n,1,20}],1] (* _Geoffrey Critzer_, Dec 23 2012 *)
%K A126778 nonn
%O A126778 2,1
%A A126778 Aleksandar M. Janjic and _Milan Janjic_, Feb 18 2007
%E A126778 Entries checked by _N. J. A. Sloane_, Mar 08 2007