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 A114870 #20 Oct 13 2016 10:30:42 %S A114870 0,1,5,25,141,911,6703,55581,513929,5248891,58724211,714554633, %T A114870 9397715341,132870076119,2009977939271,32396622193141,554297204755473, %U A114870 10034223725151731,191617109450287579,3849745645109036001 %N A114870 a(n) = A002627(n+1) - A002627(n) - n!. %H A114870 Vincenzo Librandi, <a href="/A114870/b114870.txt">Table of n, a(n) for n = 0..300</a> %F A114870 E.g.f.: (exp(x)-1)/(1-x)^2. - _Vaclav Kotesovec_, Nov 20 2012 %F A114870 a(n) = Sum_{k=0..n-1} C(n,k)*(k+1)! = Sum_{k=0..n-1} A074909(n-1,k)*(k+1)!. - _Anton Zakharov_, Sep 26 2016 %t A114870 CoefficientList[Series[(E^x-1)/(1-x)^2,{x,0,20}],x]*Range[0,20]! (* _Vaclav Kotesovec_, Nov 20 2012 *) %t A114870 Table[Sum[Binomial[n, k] (k + 1)!, {k, 0, n - 1}], {n, 0, 19}] (* _Michael De Vlieger_, Sep 27 2016 *) %Y A114870 Cf. A002627, A000522, A074909. %K A114870 nonn %O A114870 0,3 %A A114870 _Creighton Dement_, Feb 20 2006