%I #17 Sep 08 2022 08:44:54
%S 1,6,217,1308,47305,285138,10312273,62158776,2248028209,13550328030,
%T 490059837289,2953909351764,106830796500793,643938688356522,
%U 23288623577335585,140375680152370032,5076813109062656737,30601254334528310454,1106721969152081833081
%N Denominators of continued fraction convergents to sqrt(330).
%H Vincenzo Librandi, <a href="/A041623/b041623.txt">Table of n, a(n) for n = 0..200</a>
%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (0,218,0,-1).
%F G.f.: -(x^2-6*x-1) / (x^4-218*x^2+1). - _Colin Barker_, Nov 20 2013
%F a(n) = 218*a(n-2) - a(n-4) for n>3. - _Vincenzo Librandi_, Dec 22 2013
%t Denominator[Convergents[Sqrt[330], 30]] (* _Vincenzo Librandi_, Dec 22 2013 *)
%t LinearRecurrence[{0,218,0,-1},{1,6,217,1308},20] (* _Harvey P. Dale_, Sep 23 2018 *)
%o (Magma) I:=[1,6,217,1308]; [n le 4 select I[n] else 218*Self(n-2)-Self(n-4): n in [1..40]]; // _Vincenzo Librandi_, Dec 22 2013
%Y Cf. A041622, A040311.
%K nonn,frac,easy
%O 0,2
%A _N. J. A. Sloane_.
%E More terms from _Colin Barker_, Nov 20 2013
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