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%I #20 Sep 08 2022 08:44:55
%S 1,1,3,4,235,239,713,952,55929,56881,169691,226572,13310867,13537439,
%T 40385745,53923184,3167930417,3221853601,9611637619,12833491220,
%U 753954128379,766787619599,2287529367577,3054316987176,179437914623785,182492231610961
%N Denominators of continued fraction convergents to sqrt(885).
%H Vincenzo Librandi, <a href="/A042711/b042711.txt">Table of n, a(n) for n = 0..200</a>
%H <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 238, 0, 0, 0, -1).
%F G.f.: -(x^2-x-1)*(x^4+4*x^2+1) / (x^8-238*x^4+1). - _Colin Barker_, Dec 22 2013
%F a(n) = 238*a(n-4) - a(n-8) for n>7. - _Vincenzo Librandi_, Dec 22 2013
%t Denominator[Convergents[Sqrt[885], 30]] (* _Vincenzo Librandi_, Dec 22 2013 *)
%t LinearRecurrence[{0,0,0,238,0,0,0,-1},{1,1,3,4,235,239,713,952},30] (* _Harvey P. Dale_, Mar 25 2019 *)
%o (Magma) I:=[1,1,3,4,235,239,713,952]; [n le 8 select I[n] else 238*Self(n-4)-Self(n-8): n in [1..40]]; // _Vincenzo Librandi_, Dec 22 2013
%Y Cf. A042710, A040855.
%K nonn,frac,easy
%O 0,3
%A _N. J. A. Sloane_.
%E More terms from _Colin Barker_, Dec 22 2013
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