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 A156711 #41 Nov 13 2024 06:57:08
%S A156711 28,299,858,1705,2840,4263,5974,7973,10260,12835,15698,18849,22288,
%T A156711 26015,30030,34333,38924,43803,48970,54425,60168,66199,72518,79125,
%U A156711 86020,93203,100674,108433,116480,124815,133438,142349,151548,161035,170810,180873,191224,201863
%N A156711 a(n) = 144*n^2 - 161*n + 45.
%H A156711 Vincenzo Librandi, <a href="/A156711/b156711.txt">Table of n, a(n) for n = 1..10000</a>
%H A156711 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A156711 a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
%F A156711 G.f.: x*(-28 - 215*x - 45*x^2)/(x-1)^3.
%F A156711 576*a(n) + 1 = (288*n - 161)^2. - _Vincenzo Librandi_, Feb 09 2012
%F A156711 From _Elmo R. Oliveira_, Oct 31 2024: (Start)
%F A156711 E.g.f.: exp(x)*(144*x^2 - 17*x + 45) - 45.
%F A156711 a(n) = (9*n - 5)*(16*n - 9). (End)
%t A156711 LinearRecurrence[{3,-3,1},{28,299,858},40]
%t A156711 Table[144n^2-161n+45,{n,50}] (* _Harvey P. Dale_, Nov 19 2023 *)
%o A156711 (Magma) I:=[28, 299, 858]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]];
%o A156711 (PARI) a(n)=144*n^2-161*n+45 \\ _Charles R Greathouse IV_, Dec 23 2011
%K A156711 nonn,easy
%O A156711 1,1
%A A156711 _Vincenzo Librandi_, Feb 15 2009