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 A157111 #24 Dec 02 2024 15:39:22
%S A157111 30996,168838,306680,444522,582364,720206,858048,995890,1133732,
%T A157111 1271574,1409416,1547258,1685100,1822942,1960784,2098626,2236468,
%U A157111 2374310,2512152,2649994,2787836,2925678,3063520,3201362,3339204,3477046
%N A157111 a(n) = 137842*n - 106846.
%C A157111 The identity (5651522*n^2 - 8761372*n + 3395619)^2 - (1681*n^2 - 2606*n + 1010)*(137842*n - 106846)^2 = 1 can be written as A157112(n)^2 - A157110(n)*a(n)^2 = 1. - _Vincenzo Librandi_, Jan 25 2012
%H A157111 Vincenzo Librandi, <a href="/A157111/b157111.txt">Table of n, a(n) for n = 1..10000</a>
%H A157111 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).
%F A157111 a(n) = 2*a(n-1) - a(n-2). - _Vincenzo Librandi_, Jan 25 2012
%F A157111 G.f.: x*(106846*x + 30996)/(x-1)^2. - _Vincenzo Librandi_, Jan 25 2012
%t A157111 LinearRecurrence[{2,-1},{30996,168838},40] (* _Vincenzo Librandi_, Jan 25 2012 *)
%t A157111 Table[137842 n-106846,{n,30}] (* _Harvey P. Dale_, Dec 02 2024 *)
%o A157111 (PARI) a(n)=137842*n-106846 \\ _Charles R Greathouse IV_, Dec 28 2011
%o A157111 (Magma) I:=[30996, 168838]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..50]]; // _Vincenzo Librandi_, Jan 25 2012
%Y A157111 Cf. A157110, A157112.
%K A157111 nonn,easy
%O A157111 1,1
%A A157111 _Vincenzo Librandi_, Feb 23 2009