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%I #22 Sep 08 2022 08:44:55
%S 23,47,2185,4417,205367,415151,19302313,39019777,1814212055,
%T 3667443887,170516630857,344700705601,16026749088503,32398198882607,
%U 1506343897688425,3045085994259457,141580299633623447,286205685261506351
%N Numerators of continued fraction convergents to sqrt(552).
%H Vincenzo Librandi, <a href="/A042056/b042056.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 (0,94,0,-1).
%F G.f.: (1 + x)*(23 + 24*x - x^2)/(1 - 94*x^2 + x^4). - _Vincenzo Librandi_, Nov 13 2013
%F a(n) = 94*a(n-2) - a(n-4). - _Vincenzo Librandi_, Nov 14 2013
%t Numerator[Convergents[Sqrt[552], 30]] (* or *) CoefficientList[Series[(1 + x) (23 + 24 x - x^2)/(1 - 94 x^2 + x^4), {x, 0, 30}], x] (* _Vincenzo Librandi_, Nov 14 2013 *)
%t LinearRecurrence[{0,94,0,-1},{23,47,2185,4417},20] (* _Harvey P. Dale_, Mar 13 2017 *)
%o (Magma) I:=[23,47,2185,4417]; [n le 4 select I[n] else 94*Self(n-2)-Self(n-4): n in [1..25]]; // _Vincenzo Librandi_, Nov 14 2013
%Y Cf. A042057.
%K nonn,cofr,frac,easy,less
%O 0,1
%A _N. J. A. Sloane_.