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%I #18 Sep 08 2022 08:44:54
%S 18,325,11718,211249,7616682,137311525,4950831582,89252280001,
%T 3218032911618,58013844689125,2091716441720118,37708909795651249,
%U 1359612469085165082,24510733353328622725,883746013188915583182,15931938970753809120001,574433548960326043903218
%N Numerators of continued fraction convergents to sqrt(326).
%H Vincenzo Librandi, <a href="/A041614/b041614.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 (0,650,0,-1).
%F G.f.: -(x^3-18*x^2-325*x-18)/(x^4-650*x^2+1). - _Vincenzo Librandi_, Nov 05 2013
%F a(n) = 650*a(n-2)-a(n-4). - _Vincenzo Librandi_, Nov 05 2013
%t Numerator[Convergents[Sqrt[326], 30]] (*or *) CoefficientList[Series[-(x^3 - 18 x^2 - 325 x - 18)/(x^4 - 650 x^2 + 1), {x, 0, 30}], x] (* _Vincenzo Librandi_, Nov 05 2013 *)
%t LinearRecurrence[{0,650,0,-1},{18,325,11718,211249},30] (* _Harvey P. Dale_, Jan 01 2014 *)
%o (Magma) I:=[18,325,11718,211249]; [n le 4 select I[n] else 650*Self(n-2)-Self(n-4): n in [1..20]]; // _Vincenzo Librandi_, Nov 05 2013
%Y Cf. A041615.
%K nonn,cofr,frac,easy
%O 0,1
%A _N. J. A. Sloane_.
%E More terms from _Colin Barker_, Nov 09 2013