A041697 - OEIS

%I #17 Sep 08 2022 08:44:54

%S 1,5,11,60,2291,11515,25321,138120,5273881,26507525,58288931,

%T 317952180,12140471771,61020311035,134181093841,731925780240,

%U 27947360742961,140468729495045,308884819733051,1684892828160300,64334812289824451,323358954277282555

%N Denominators of continued fraction convergents to sqrt(368).

%H Vincenzo Librandi, <a href="/A041697/b041697.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 (0,0,0,2302,0,0,0,-1).

%F G.f.: -(x^2-5*x-1)*(x^4+12*x^2+1) / ((x^4-48*x^2+1)*(x^4+48*x^2+1)). - _Colin Barker_, Nov 22 2013

%F a(n) = 2302*a(n-4) - a(n-8) for n>7. - _Vincenzo Librandi_, Dec 23 2013

%t Denominator[Convergents[Sqrt[368], 30]] (* _Vincenzo Librandi_, Dec 23 2013 *)

%t LinearRecurrence[{0,0,0,2302,0,0,0,-1},{1,5,11,60,2291,11515,25321,138120},30] (* _Harvey P. Dale_, Nov 21 2015 *)

%o (Magma) I:=[1,5,11,60,2291,11515,25321,138120]; [n le 8 select I[n] else 2302*Self(n-4)-Self(n-8): n in [1..40]]; // _Vincenzo Librandi_, Dec 23 2013

%Y Cf. A041696, A040348.

%K nonn,frac,easy

%O 0,2

%A _N. J. A. Sloane_.

%E More terms from _Colin Barker_, Nov 22 2013