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%I #19 Sep 08 2022 08:44:54
%S 1,1,2,3,5,18,23,41,64,105,2584,2689,5273,7962,13235,47667,60902,
%T 108569,169471,278040,6842431,7120471,13962902,21083373,35046275,
%U 126222198,161268473,287490671,448759144,736249815,18118754704,18855004519,36973759223,55828763742
%N Denominators of continued fraction convergents to sqrt(159).
%H Vincenzo Librandi, <a href="/A041293/b041293.txt">Table of n, a(n) for n = 0..200</a>
%H <a href="/index/Rec#order_20">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 2648, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).
%F G.f.: -(x^4-3*x^3+4*x^2-2*x+1)*(x^4+2*x^3+4*x^2+3*x+1)*(x^10-21*x^5-1) / (x^20-2648*x^10+1). - _Colin Barker_, Nov 14 2013
%F a(n) = 2648*a(n-10) - a(n-20). - _Vincenzo Librandi_, Dec 15 2013
%t Denominator[Convergents[Sqrt[159], 30]] (* _Vincenzo Librandi_, Dec 15 2013 *)
%o (Magma) I:=[1, 1, 2, 3, 5, 18, 23, 41, 64, 105, 2584, 2689, 5273, 7962, 13235, 47667, 60902, 108569, 169471, 278040]; [n le 20 select I[n] else 2648*Self(n-10)-Self(n-20): n in [1..40]]; // _Vincenzo Librandi_, Dec 15 2013
%Y Cf. A041292, A010208.
%K nonn,frac,easy
%O 0,3
%A _N. J. A. Sloane_.
%E More terms from _Colin Barker_, Nov 14 2013
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