%I #18 Nov 04 2024 14:58:42
%S 1,26,1353,35204,1831961,47666190,2480473841,64539986056,
%T 3358559748753,87387093453634,4547487419337721,118322059996234380,
%U 6157294607223525481,160207981847807896886,8336972350693234163553,216921489099871896149264
%N Denominators of continued fraction convergents to sqrt(678).
%H Vincenzo Librandi, <a href="/A042303/b042303.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 (0,1354,0,-1).
%F G.f.: -(x^2-26*x-1) / (x^4-1354*x^2+1). - _Colin Barker_, Dec 07 2013
%F a(n) = 1354*a(n-2) - a(n-4) for n>3. - _Vincenzo Librandi_, Jan 19 2014
%t Denominator[Convergents[Sqrt[678], 30]] (* _Vincenzo Librandi_, Jan 19 2014 *)
%t LinearRecurrence[{0,1354,0,-1},{1,26,1353,35204},20] (* _Harvey P. Dale_, Nov 04 2024 *)
%o (Magma) I:=[1,26,1353,35204]; [n le 4 select I[n] else 1354*Self(n-2)-Self(n-4): n in [1..30]]; // _Vincenzo Librandi_, Jan 19 2014
%Y Cf. A042302, A040651.
%K nonn,frac,easy
%O 0,2
%A _N. J. A. Sloane_.
%E More terms from _Colin Barker_, Dec 07 2013