%I #17 Sep 08 2022 08:44:55
%S 26,27,1430,1457,77194,78651,4167046,4245697,224943290,229188987,
%T 12142770614,12371959601,655484669866,667856629467,35384029402150,
%U 36051886031617,1910082103046234,1946133989077851
%N Numerators of continued fraction convergents to sqrt(728).
%H Vincenzo Librandi, <a href="/A042402/b042402.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, 54, 0, -1).
%F G.f.: (26 +27*x +26*x^2 -x^3)/(1 -54*x^2 +x^4). - _Vincenzo Librandi_, Nov 23 2013
%F a(n) = 54*a(n-2) - a(n-4). - _Vincenzo Librandi_, Nov 23 2013
%t Numerator[Convergents[Sqrt[728], 30]] (* _Harvey P. Dale_, Feb 24 2013 *)
%t CoefficientList[Series[(26 + 27 x + 26 x^2 - x^3)/(1 - 54 x^2 + x^4), {x, 0, 30}], x] (* _Vincenzo Librandi_, Nov 23 2013 *)
%o (Magma) I:=[26, 27, 1430, 1457]; [n le 4 select I[n] else 54*Self(n-2)-Self(n-4): n in [1..30]]; // _Vincenzo Librandi_, Nov 23 2013
%Y Cf. A042403.
%K nonn,cofr,frac,easy
%O 0,1
%A _N. J. A. Sloane_.
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