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 A157761 #18 Sep 08 2022 08:45:42
%S A157761 244754,542508,840262,1138016,1435770,1733524,2031278,2329032,2626786,
%T A157761 2924540,3222294,3520048,3817802,4115556,4413310,4711064,5008818,
%U A157761 5306572,5604326,5902080,6199834,6497588,6795342,7093096,7390850
%N A157761 a(n) = 297754*n - 53000.
%C A157761 The identity (15780962*n^2-5618000*n+500001)^2-(2809*n^2-1000*n+89)*(297754*n-53000)^2=1 can be written as A157762(n)^2-A157760(n)*a(n)^2=1.
%H A157761 Vincenzo Librandi, <a href="/A157761/b157761.txt">Table of n, a(n) for n = 1..10000</a>
%H A157761 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A157761 a(n) = 2*a(n-1) - a(n-2) = 3*a(n-1) - 3*a(n-2) + a(n-3).
%F A157761 G.f.: x*(244754 + 53000*x)/(1 - x)^2.
%t A157761 LinearRecurrence[{2, -1}, {244754, 542508}, 50]
%o A157761 (Magma) I:=[244754, 542508]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..50]];
%o A157761 (PARI) a(n) = 297754n - 53000;
%Y A157761 Cf. A157760, A157762.
%K A157761 nonn,easy
%O A157761 1,1
%A A157761 _Vincenzo Librandi_, Mar 06 2009