Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #17 Sep 08 2022 08:44:54
%S 1,2,5,12,461,934,2329,5592,214825,435242,1085309,2605860,100107989,
%T 202821838,505751665,1214325168,46650108049,94514541266,235679190581,
%U 565872922428,21738850242845,44043573408118,109825997059081,263695567526280,10130257563057721
%N Denominators of continued fraction convergents to sqrt(377).
%H Vincenzo Librandi, <a href="/A041715/b041715.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 (0,0,0,466,0,0,0,-1).
%F G.f.: -(x^2-2*x-1)*(x^4+6*x^2+1) / (x^8-466*x^4+1). - _Colin Barker_, Nov 22 2013
%F a(n) = 466*a(n-4) - a(n-8) for n>7. - _Vincenzo Librandi_, Dec 23 2013
%t Denominator[Convergents[Sqrt[377], 30]] (* _Vincenzo Librandi_, Dec 23 2013 *)
%t LinearRecurrence[{0,0,0,466,0,0,0,-1},{1,2,5,12,461,934,2329,5592},40] (* _Harvey P. Dale_, Jul 24 2019 *)
%o (Magma) I:=[1,2,5,12,461,934,2329,5592]; [n le 8 select I[n] else 466*Self(n-4)-Self(n-8): n in [1..40]]; // _Vincenzo Librandi_, Dec 23 2013
%Y Cf. A041714, A040357.
%K nonn,frac,easy
%O 0,2
%A _N. J. A. Sloane_.
%E More terms from _Colin Barker_, Nov 22 2013