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%I #15 Sep 08 2022 08:44:55
%S 30,121,7290,29281,1764150,7085881,426917010,1714753921,103312152270,
%T 414963363001,25001113932330,100419419092321,6050166259471590,
%U 24301084456978681,1464115233678192450,5880762019169748481,354309836383863101310,1423120107554622153721
%N Numerators of continued fraction convergents to sqrt(915).
%H Vincenzo Librandi, <a href="/A042768/b042768.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, 242, 0, -1).
%F G.f.: (30 +121*x +30*x^2 -x^3)/(1 -242*x^2 +x^4). - _Vincenzo Librandi_, Dec 04 2013
%F a(n) = 242*a(n-2) - a(n-4). - _Vincenzo Librandi_, Dec 04 2013
%t Numerator[Convergents[Sqrt[915], 30]] (* or *) CoefficientList[Series[(30 + 121 x + 30 x^2 - x^3)/(1 - 242 x^2 + x^4), {x, 0, 30}], x] (* _Vincenzo Librandi_, Dec 04 2013 *)
%o (Magma) I:=[30, 121, 7290, 29281]; [n le 4 select I[n] else 242*Self(n-2)-Self(n-4): n in [1..30]]; // _Vincenzo Librandi_, Dec 04 2013
%Y Cf. A042769.
%K nonn,cofr,frac,easy
%O 0,1
%A _N. J. A. Sloane_.
%E More terms from _Vincenzo Librandi_, Dec 04 2013
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