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 A165793 #13 Apr 08 2016 19:53:16
%S A165793 1,-1,-6,-24,-104,-530,-3192,-22358,-178880,-1609938,-16099400,
%T A165793 -177093422,-2125121088,-27626574170,-386772038408,-5801580576150,
%U A165793 -92825289218432,-1578029916713378,-28404538500840840
%N A165793 a(0)=1, a(n)=n*(a(n-1)-2).
%H A165793 G. C. Greubel, <a href="/A165793/b165793.txt">Table of n, a(n) for n = 0..250</a>
%F A165793 a(n) = n! - 2*floor(e*n!)+2 , n>0. - _Gary Detlefs_, Jun 19 2010
%t A165793 RecurrenceTable[{a[0]==1,a[n]==n*(a[n-1]-2)},a[n],{n,30}] (* _Harvey P. Dale_, Jul 19 2011 *)
%t A165793 FoldList[#1*#2 - 2 #2 &, 1, Range[25]] (* _G. C. Greubel_, Apr 08 2016 *)
%K A165793 sign
%O A165793 0,3
%A A165793 _Philippe Deléham_, Sep 26 2009
%E A165793 Corrected by _Harvey P. Dale_, Jul 19 2011