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%I #15 Sep 08 2022 08:44:54
%S 1,3,4,7,18,43,61,104,373,12040,36493,48533,85026,218585,522196,
%T 740781,1262977,4529712,146213761,443170995,589384756,1032555751,
%U 2654496258,6341548267,8996044525,15337592792,55008822901,1775619925624,5381868599773,7157488525397
%N Denominators of continued fraction convergents to sqrt(265).
%H Vincenzo Librandi, <a href="/A041497/b041497.txt">Table of n, a(n) for n = 0..200</a>
%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,0,0,0,12144,0,0,0,0,0,0,0,0,1).
%F G.f.: -(x^16 -3*x^15 +4*x^14 -7*x^13 +18*x^12 -43*x^11 +61*x^10 -104*x^9 +373*x^8 +104*x^7 +61*x^6 +43*x^5 +18*x^4 +7*x^3 +4*x^2 +3*x +1) / (x^18 +12144*x^9 -1). - _Colin Barker_, Nov 18 2013
%F a(n) = 12144*a(n-9) + a(n-18) for n>17, - _Vincenzo Librandi_, Dec 19 2013
%t Denominator[Convergents[Sqrt[265], 30]] (* _Vincenzo Librandi_, Dec 19 2013 *)
%o (Magma) I:=[1,3,4,7,18,43,61,104,373,12040,36493,48533, 85026,218585,522196,740781,1262977,4529712]; [n le 18 select I[n] else 12144*Self(n-9)+Self(n-18): n in [1..30]]; // _Vincenzo Librandi_, Dec 19 2013
%Y Cf. A041496, A040248.
%K nonn,frac,easy
%O 0,2
%A _N. J. A. Sloane_.
%E More terms from _Colin Barker_, Nov 18 2013
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