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 A162256 #21 Aug 30 2018 23:19:42 %S A162256 2,15,45,98,180,297,455,660,918,1235,1617,2070,2600,3213,3915,4712, %T A162256 5610,6615,7733,8970,10332,11825,13455,15228,17150,19227,21465,23870, %U A162256 26448,29205,32147,35280,38610,42143,45885,49842,54020,58425,63063,67940 %N A162256 a(n) = (2*n^3 + 5*n^2 - 3*n)/2. %C A162256 Row sums from A154680. %H A162256 Vincenzo Librandi, <a href="/A162256/b162256.txt">Table of n, a(n) for n = 1..1000</a> %H A162256 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1). %F A162256 From _Vincenzo Librandi_, Mar 04 2012: (Start) %F A162256 G.f.: x*(2 + 7*x - 3*x^2)/(1-x)^4. %F A162256 a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). (End) %t A162256 LinearRecurrence[{4,-6,4,-1}, {2, 15, 45, 98}, 50] (* or *) CoefficientList[Series[(2+7*x-3*x^2)/(1-x)^4,{x,0,39}],x] (* _Vincenzo Librandi_, Mar 04 2012 *) %o A162256 (PARI) n*(5*n-3)/2+n^3 \\ _Charles R Greathouse IV_, Jan 11 2012 %K A162256 nonn,easy %O A162256 1,1 %A A162256 _Vincenzo Librandi_, Jun 29 2009