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 A154277 #37 Oct 16 2022 09:58:06
%S A154277 17,26,197,530,1025,1682,2501,3482,4625,5930,7397,9026,10817,12770,
%T A154277 14885,17162,19601,22202,24965,27890,30977,34226,37637,41210,44945,
%U A154277 48842,52901,57122,61505,66050,70757,75626,80657,85850,91205,96722
%N A154277 a(n) = 81*n^2 - 72*n + 17.
%C A154277 The identity (81*n^2 + 90*n + 26)^2 - (9*n^2 + 10*n + 3)*(27*n + 15)^2 = 1 can be written as a(n+1)^2 - A154254(n+1)*A154267(n)^2 = 1. - _Vincenzo Librandi_, Feb 03 2012
%H A154277 Vincenzo Librandi, <a href="/A154277/b154277.txt">Table of n, a(n) for n = 0..10000</a>
%H A154277 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A154277 G.f.: (17 - 25*x + 170*x^2)/(1-x)^3. - _Vincenzo Librandi_, Feb 02 2012
%F A154277 a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - _Vincenzo Librandi_, Feb 02 2012
%F A154277 a(n) = A017221(n-1)^2 + 1 with A017221(-1) = -4. - _Bruno Berselli_, Feb 02 2012
%F A154277 E.g.f.: (17 + 9*x + 81*x^2)*exp(x). - _G. C. Greubel_, Sep 09 2016
%t A154277 LinearRecurrence[{3, -3, 1}, {26, 197, 530}, 40] (* _Vincenzo Librandi_, Feb 02 2012 *)
%t A154277 Table[81n^2-72n+17,{n,0,40}] (* _Harvey P. Dale_, Oct 16 2022 *)
%o A154277 (Magma) I:=[26, 197, 530]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]]; // _Vincenzo Librandi_, Feb 02 2012
%o A154277 (PARI) for(n=0, 22, print1(81*n^2 - 72*n + 17", ")); \\ _Vincenzo Librandi_, Feb 02 2012
%Y A154277 Cf. A154254, A154267.
%K A154277 nonn,easy
%O A154277 0,1
%A A154277 _Vincenzo Librandi_, Jan 06 2009
%E A154277 92205 replaced by 91205 - _R. J. Mathar_, Jan 07 2009
%E A154277 Edited by _Charles R Greathouse IV_, Aug 09 2010