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 A144640 #32 Sep 08 2022 08:45:38
%S A144640 3,17,48,102,185,303,462,668,927,1245,1628,2082,2613,3227,3930,4728,
%T A144640 5627,6633,7752,8990,10353,11847,13478,15252,17175,19253,21492,23898,
%U A144640 26477,29235,32178,35312,38643,42177,45920,49878,54057,58463,63102,67980,73103
%N A144640 Row sums from A144562.
%C A144640 Row 2 of the convolution array A213833. - _Clark Kimberling_, Jul 04 2012
%H A144640 Vincenzo Librandi, <a href="/A144640/b144640.txt">Table of n, a(n) for n = 1..10000</a>
%H A144640 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F A144640 a(n) = n*(2*n^2 + 5*n - 1)/2. - _Jon E. Schoenfield_, Jun 24 2010
%F A144640 G.f.: x*(3+5*x-2*x^2)/(1-x)^4. - _Vincenzo Librandi_, Jul 06 2012
%F A144640 a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). - _Vincenzo Librandi_, Jul 06 2012
%F A144640 E.g.f.: x*(6 + 11*x + 2*x^2)*exp(x)/2. - _G. C. Greubel_, Mar 01 2021
%p A144640 A144640:= n-> n*(2*n^2 +5*n -1)/2; seq(A144640(n), n=1..40); # _G. C. Greubel_, Mar 01 2021
%t A144640 CoefficientList[Series[(3+5*x-2*x^2)/(1-x)^4,{x,0,40}],x] (* _Vincenzo Librandi_, Jul 06 2012 *)
%o A144640 (Magma) I:=[3, 17, 48, 102]; [n le 4 select I[n] else 4*Self(n-1) -6*Self(n-2) +4*Self(n-3) -Self(n-4): n in [1..50]]; // _Vincenzo Librandi_, Jul 06 2012
%o A144640 (Sage) [n*(2*n^2 +5*n -1)/2 for n in (1..40)] # _G. C. Greubel_, Mar 01 2021
%Y A144640 Cf. A144562, A213833.
%K A144640 nonn,easy
%O A144640 1,1
%A A144640 _Vincenzo Librandi_, Jan 21 2009, Jun 29 2009