A020412 - OEIS

%I #14 Jul 11 2021 01:31:05

%S 3541,5849,7165,7501,8933,9473,9857,11497,13753,13901,14218,15793,

%T 17597,18917,20609,24202,24746,25121,25906,25913,26177,28465,29437,

%U 31466,33185,33386,33562,34913,35989,38293,39565,39626,40345,40762,41546,41938,44761

%N Numbers k such that the continued fraction for sqrt(k) has period 73.

%t cfp73Q[n_]:=Module[{s=Sqrt[n]},!IntegerQ[s]&&Length[ContinuedFraction[s][[2]]] == 73]; Select[Range[45000],cfp73Q] (* _Harvey P. Dale_, Feb 26 2013 *)

%Y Cf. A003285.

%K nonn

%O 1,1

%A _David W. Wilson_