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Denominators of continued fraction convergents to sqrt(370).
2

%I #18 Sep 08 2022 08:44:54

%S 1,4,17,650,2617,11118,425101,1711522,7271189,278016704,1119338005,

%T 4755368724,181823349517,732048766792,3110018416685,118912748600822,

%U 478761012819973,2033956799880714,77769119408287105,313110434433029134,1330210857140403641

%N Denominators of continued fraction convergents to sqrt(370).

%H Vincenzo Librandi, <a href="/A041701/b041701.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 (0,0,654,0,0,1).

%F G.f.: -(x^4-4*x^3+17*x^2+4*x+1) / (x^6+654*x^3-1). - _Colin Barker_, Nov 22 2013

%F a(n) = 654*a(n-3) + a(n-6) for n>5. - _Vincenzo Librandi_, Dec 23 2013

%t Denominator[Convergents[Sqrt[370], 20]] (* _Harvey P. Dale_, Nov 01 2011 *)

%t CoefficientList[Series[-(x^4 - 4 x^3 + 17 x^2 + 4 x + 1)/(x^6 + 654 x^3 - 1), {x, 0, 30}], x] (* _Vincenzo Librandi_, Dec 23 2013 *)

%o (Magma) I:=[1,4,17,650,2617,11118]; [n le 6 select I[n] else 654*Self(n-3)+Self(n-6): n in [1..40]]; // _Vincenzo Librandi_, Dec 23 2013

%Y Cf. A041700, A040350.

%K nonn,frac,easy

%O 0,2

%A _N. J. A. Sloane_.

%E More terms from _Colin Barker_, Nov 22 2013