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 A163661 #22 Dec 17 2019 05:29:47
%S A163661 0,12,35,75,138,230,357,525,740,1008,1335,1727,2190,2730,3353,4065,
%T A163661 4872,5780,6795,7923,9170,10542,12045,13685,15468,17400,19487,21735,
%U A163661 24150,26738,29505,32457,35600,38940,42483,46235,50202,54390,58805,63453
%N A163661 a(n) = n*(2*n^2 + 5*n + 17)/2.
%H A163661 Vincenzo Librandi, <a href="/A163661/b163661.txt">Table of n, a(n) for n = 0..1000</a>
%H A163661 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F A163661 Row sums from A163657: a(n) = Sum_{m=1..n} (2*m*n + m + n + 8).
%F A163661 a(n) = A163655(n) + 2*n.
%F A163661 G.f.: x*(12 - 13*x + 7*x^2)/(x-1)^4.
%F A163661 a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).
%F A163661 E.g.f.: (1/2)*x*(24 + 11*x + 2*x^2)*exp(x). - _G. C. Greubel_, Aug 01 2017
%t A163661 CoefficientList[Series[x*(12-13*x+7*x^2)/(x-1)^4,{x,0,40}],x] (* or *) LinearRecurrence[{4, -6, 4, -1}, {0, 12, 35, 75}, 50](* _Vincenzo Librandi_, Mar 06 2012 *)
%o A163661 (PARI) x='x+O('x^50); concat([0], Vec(x*(12-13*x+7*x^2)/(x-1)^4)) \\ _G. C. Greubel_, Aug 01 2017
%Y A163661 Cf. A163657.
%K A163661 nonn,easy
%O A163661 0,2
%A A163661 _Vincenzo Librandi_, Aug 02 2009
%E A163661 Edited and a(31) corrected by _R. J. Mathar_, Aug 05 2009