%I #14 Mar 19 2017 08:47:43
%S 1,1,3,4,11,15,26,249,1022,9447,10469,19916,50301,70217,190735,260952,
%T 7497391,7758343,23014077,30772420,84558917,115331337,199890254,
%U 1914343623,7857264746,72629726337
%N Denominators of continued fraction convergents to sqrt(217).
%H Vincenzo Librandi, <a href="/A041405/b041405.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_32">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7688126, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1).
%F a(n) = 7688126*a(n-16) - a(n-32) for n>31. [_Bruno Berselli_, Dec 18 2013]
%t Denominator[Convergents[Sqrt[217],30]] (* _Harvey P. Dale_, Mar 20 2012 *)
%Y Cf. A041404.
%K nonn,frac,easy
%O 0,3
%A _N. J. A. Sloane_.