%I #16 Sep 08 2022 08:44:54
%S 1,1,4,5,194,199,791,990,38411,39401,156614,196015,7605184,7801199,
%T 31008781,38809980,1505788021,1544598001,6139582024,7684180025,
%U 298138422974,305822602999,1215606231971,1521428834970,59029901960831,60551330795801
%N Denominators of continued fraction convergents to sqrt(392).
%H Vincenzo Librandi, <a href="/A041745/b041745.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 (0,0,0,198,0,0,0,-1).
%F G.f.: -(x^2-x-1)*(x^4+5*x^2+1) / ((x^4-14*x^2-1)*(x^4+14*x^2-1)). - _Colin Barker_, Nov 23 2013
%F a(n) = 198*a(n-4) - a(n-8) for n>7. - _Vincenzo Librandi_, Dec 23 2013
%t Denominator[Convergents[Sqrt[392], 30]] (* _Vincenzo Librandi_, Dec 23 2013 *)
%o (Magma) I:=[1,1,4,5,194,199,791,990]; [n le 8 select I[n] else 198*Self(n-4)-Self(n-8): n in [1..40]]; // _Vincenzo Librandi_, Dec 23 2013
%Y Cf. A041744, A040372.
%K nonn,frac,easy
%O 0,3
%A _N. J. A. Sloane_.
%E More terms from _Colin Barker_, Nov 23 2013