%I #19 Sep 08 2022 08:44:54
%S 1,2,9,182,737,1656,66977,135610,609417,12323950,49905217,112134384,
%T 4535280577,9182695538,41266062729,834503950118,3379281863201,
%U 7593067676520,307101988924001,621797045524522,2794290171022089,56507600465966302
%N Denominators of continued fraction convergents to sqrt(418).
%H Vincenzo Librandi, <a href="/A041795/b041795.txt">Table of n, a(n) for n = 0..200</a>
%H <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 67714, 0, 0, 0, 0, 0, -1).
%F G.f.: -(x^10 -2*x^9 +9*x^8 -182*x^7 +737*x^6 -1656*x^5 -737*x^4 -182*x^3 -9*x^2 -2*x-1) / (x^12-67714*x^6+1). - _Colin Barker_, Nov 24 2013
%F a(n) = 67714*a(n-6) - a(n-12) for n>11. - _Vincenzo Librandi_, Dec 24 2013
%t Denominator[Convergents[Sqrt[418], 30]] (* _Vincenzo Librandi_, Dec 24 2013 *)
%o (Magma) I:=[1,2,9,182,737,1656,66977,135610,609417, 12323950,49905217,112134384]; [n le 12 select I[n] else 67714*Self(n-6)-Self(n-12): n in [1..50]]; // _Vincenzo Librandi_, Dec 24 2013
%Y Cf. A041794, A040397.
%K nonn,frac,easy
%O 0,2
%A _N. J. A. Sloane_.
%E More terms from _Colin Barker_, Nov 24 2013