%I #20 Oct 06 2023 16:34:31
%S 1,23,1059,24380,1122539,25842777,1189890281,27393319240,
%T 1261282575321,29036892551623,1336958339949979,30779078711401140,
%U 1417174579064402419,32625794397192656777,1502203716849926614161,34583311281945504782480,1592334522686343146608241
%N Denominators of continued fraction convergents to sqrt(531).
%H Vincenzo Librandi, <a href="/A042015/b042015.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, 1060, 0, -1).
%F G.f.: -(x^2-23*x-1) / (x^4-1060*x^2+1). - _Colin Barker_, Nov 29 2013
%F a(n) = 1060*a(n-2) - a(n-4) for n>3. - _Vincenzo Librandi_, Jan 12 2014
%t Denominator[Convergents[Sqrt[531], 40]] (* _Vincenzo Librandi_, Jan 12 2014 *)
%t LinearRecurrence[{0,1060,0,-1},{1,23,1059,24380},20] (* _Harvey P. Dale_, Oct 06 2023 *)
%o (Magma) I:=[1,23,1059,24380]; [n le 4 select I[n] else 1060*Self(n-2)-Self(n-4): n in [1..20]]; // _Vincenzo Librandi_, Jan 12 2014
%Y Cf. A042014, A040507.
%K nonn,frac,easy,less
%O 0,2
%A _N. J. A. Sloane_.
%E More terms from _Colin Barker_, Nov 29 2013