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 A210661 #22 Sep 24 2013 15:35:38
%S A210661 1,1,5,41,464,6679,116534,2387223,56126216,1488936405,43981641232,
%T A210661 1431351648253,50877935705904,1960987188622955,81454893191133968,
%U A210661 3627186997857749259,172364960657294194944,8705953783492490785801,465732966748611591349632,26305402198153236286685809,1564288763576093814775234304
%N A210661 The total number of ways to linearly order the connected components of each functional digraph over all functions f:{1,2,...,n}->{1,2,...,n}.
%C A210661 Sum_{k=1,2,...,n}:A060281(n,k)*k!
%F A210661 E.g.f.: 1/(1-log(1/(1-T(x)))) where T(x) is the e.g.f. for A000169.
%F A210661 a(n) ~ n! * exp((2*n*exp(1)-exp(1)-n)*exp(-1))/(exp(1)-1)^(n+1). - _Vaclav Kotesovec_, Sep 24 2013
%t A210661 nn=20;t=Sum[n^(n-1)x^n/n!,{n,1,nn}];a=Log[1/(1-t)];Range[0,nn]!CoefficientList[Series[1/(1-a),{x,0,nn}],x]
%K A210661 nonn
%O A210661 0,3
%A A210661 _Geoffrey Critzer_, Mar 30 2012