A020438 - OEIS

%I #12 Jul 11 2021 07:24:04

%S 4201,4801,5449,6073,7333,7741,8369,11089,12073,13121,13621,15754,

%T 16285,17389,18385,19429,21589,21697,23962,24181,24685,25997,26281,

%U 26513,26842,29098,29593,29914,33053,35461,36149,37090,39637,39733,40265,42293,43669

%N Numbers k such that the continued fraction for sqrt(k) has period 99.

%t cf99Q[n_]:=Module[{s=Sqrt[n]},If[IntegerQ[s],1,Length[ ContinuedFraction[ s][[2]]]]==99]; Select[Range[44000],cf99Q] (* _Harvey P. Dale_, Aug 26 2017 *)

%K nonn

%O 1,1

%A _David W. Wilson_