A041617 - OEIS

%I #19 Sep 08 2022 08:44:54

%S 1,12,433,5208,187921,2260260,81557281,980947632,35395672033,

%T 425729012028,15361640105041,184765410272520,6666916409915761,

%U 80187762329261652,2893426360263335233,34801304085489284448,1255740373437877575361

%N Denominators of continued fraction convergents to sqrt(327).

%H Vincenzo Librandi, <a href="/A041617/b041617.txt">Table of n, a(n) for n = 0..200</a>

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0, 434, 0, -1).

%F G.f.: -(x^2-12*x-1) / (x^4-434*x^2+1). - _Colin Barker_, Nov 20 2013

%F a(n) = 434*a(n-2) - a(n-4) for n>3, - _Vincenzo Librandi_, Dec 22 2013

%t Denominator[Convergents[Sqrt[327], 30]] (* _Vincenzo Librandi_, Dec 22 2013 *)

%o (Magma) I:=[1,12,433,5208]; [n le 4 select I[n] else 434*Self(n-2)-Self(n-4): n in [1..40]]; // _Vincenzo Librandi_, Dec 22 2013

%Y Cf. A041616, A040308.

%K nonn,frac,easy

%O 0,2

%A _N. J. A. Sloane_.

%E More terms from _Colin Barker_, Nov 20 2013