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A174751 x-values in the solution to x^2-39*y^2=1. 2

%I

%S 1,25,1249,62425,3120001,155937625,7793761249,389532124825,

%T 19468812480001,973051091875225,48633085781281249,2430681237972187225,

%U 121485428812828080001,6071840759403431812825,303470552541358762561249

%N x-values in the solution to x^2-39*y^2=1.

%C The corresponding values of y of this Pell equation are in A174776.

%H Vincenzo Librandi, <a href="/A174751/b174751.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 (50,-1).

%F a(n) = 50*a(n-1)-a(n-2) with a(1)=1, a(2)=25.

%F G.f.: x*(1-25*x)/(1-50*x+x^2).

%t LinearRecurrence[{50,-1},{1,25},30]

%o (MAGMA) I:=[1, 25]; [n le 2 select I[n] else 50*Self(n-1)-Self(n-2): n in [1..20]];

%Y Cf. A174776.

%K nonn,easy

%O 1,2

%A _Vincenzo Librandi_, Apr 13 2010

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Last modified July 24 05:05 EDT 2021. Contains 346273 sequences. (Running on oeis4.)