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%I #13 Sep 08 2022 08:45:51
%S 0,12,1320,145188,15969360,1756484412,193197315960,21249948271188,
%T 2337301112514720,257081872428348012,28276668666005766600,
%U 3110176471388205977988,342091135184036651812080
%N y-values in the solution to x^2 - 21*y^2 = 1.
%C The corresponding values of x of this Pell equation are in A114049.
%H Vincenzo Librandi, <a href="/A174745/b174745.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 (110,-1).
%F a(n) = 110*a(n-1)-a(n-2) with a(1)=0, a(2)=12.
%F G.f.: 12*x^2/(1-110*x+x^2).
%t LinearRecurrence[{110,-1},{0,12},30]
%o (Magma) I:=[0, 12]; [n le 2 select I[n] else 110*Self(n-1)-Self(n-2): n in [1..20]];
%Y Cf. A114049.
%K nonn,easy
%O 1,2
%A _Vincenzo Librandi_, Apr 14 2010