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%I #19 Sep 08 2022 08:44:54
%S 1,3,13,42,1357,4113,17809,57540,1859089,5634807,24398317,78829758,
%T 2546950573,7719681477,33425676481,107996710920,3489320425921,
%U 10575957988683,45793152380653,147955415130642,4780366436561197,14489054724814233,62736585335818129
%N Denominators of continued fraction convergents to sqrt(266).
%H Vincenzo Librandi, <a href="/A041499/b041499.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 (0,0,0,1370,0,0,0,-1).
%F G.f.: -(x^2-3*x-1)*(x^4+14*x^2+1) / (x^8-1370*x^4+1). - _Colin Barker_, Nov 18 2013
%F a(n) = 1370*a(n-4) - a(n-8) for n>7. - _Vincenzo Librandi_, Dec 19 2013
%t Denominator/@Convergents[Sqrt[266], 20] (* _Harvey P. Dale_, Apr 11 2011 *)
%t CoefficientList[Series[(1 + 3 x - x^2) (x^4 + 14 x^2 + 1)/(x^8 - 1370 x^4 + 1), {x, 0, 30}], x] (* _Vincenzo Librandi_, Dec 19 2013 *)
%o (Magma) I:=[1,3,13,42,1357,4113,17809,57540]; [n le 8 select I[n] else 1370*Self(n-4)-Self(n-8): n in [1..30]]; // _Vincenzo Librandi_, Dec 19 2013
%Y Cf. A041498, A040249.
%K nonn,frac,easy
%O 0,2
%A _N. J. A. Sloane_.
%E More terms from _Colin Barker_, Nov 18 2013
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