%I #13 Sep 08 2022 08:45:51
%S 0,39,13260,4508361,1532829480,521157514839,177192022215780,
%T 60244766395850361,20483043382566906960,6964174505306352516039,
%U 2367798848760777288546300,805044644404158971753225961
%N y-values in the solution to x^2 - 19*y^2 = 1.
%C The corresponding values of x of this Pell equation are in A114048.
%H Vincenzo Librandi, <a href="/A174765/b174765.txt">Table of n, a(n) for n = 1..200</a>
%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (340,-1).
%F a(n) = 340*a(n-1)-a(n-2) with a(1)=0, a(2)=39.
%F G.f.: 39*x^2/(1-340*x+x^2).
%t LinearRecurrence[{340,-1},{0,39},30]
%o (Magma) I:=[0, 39]; [n le 2 select I[n] else 340*Self(n-1)-Self(n-2): n in [1..20]];
%Y Cf. A114048.
%K nonn,easy
%O 1,2
%A _Vincenzo Librandi_, Apr 14 2010
|