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A042197 Denominators of continued fraction convergents to sqrt(623). 2

%I

%S 1,1,24,25,1224,1249,29951,31200,1527551,1558751,37378824,38937575,

%T 1906382424,1945319999,46648742401,48594062400,2379163737601,

%U 2427757800001,58217593137624,60645350937625,2969194438143624,3029839789081249,72655509587012351

%N Denominators of continued fraction convergents to sqrt(623).

%H Vincenzo Librandi, <a href="/A042197/b042197.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 (0,0,0,1248,0,0,0,-1).

%F G.f.: -(x^2-x-1)*(x^4+25*x^2+1) / (x^8-1248*x^4+1). - _Colin Barker_, Dec 04 2013

%F a(n) = 1248*a(n-4) - a(n-8) for n>7. - _Vincenzo Librandi_, Jan 16 2014

%t Denominator[Convergents[Sqrt[623], 30]] (* _Harvey P. Dale_, Jun 28 2012 *)

%o (MAGMA) I:=[1,1,24,25,1224,1249,29951,31200]; [n le 8 select I[n] else 1248*Self(n-4)-Self(n-8): n in [1..30]]; // _Vincenzo Librandi_, Jan 16 2014

%Y Cf. A042196, A040598.

%K nonn,cofr,frac,easy,less

%O 0,3

%A _N. J. A. Sloane_.

%E More terms from _Colin Barker_, Dec 04 2013

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Last modified June 2 18:09 EDT 2020. Contains 334787 sequences. (Running on oeis4.)