A020413 - OEIS

%I #14 Jul 11 2021 01:31:49

%S 2038,2083,3193,3369,3499,3841,3909,4211,4219,4601,5257,5446,5949,

%T 6070,6457,6614,6742,7169,7211,7819,8193,8365,8491,8626,8656,8788,

%U 8833,9057,9142,9227,9334,9457,9557,9832,9889,10036,10054,10147,10259,10339,10441

%N Numbers k such that the continued fraction for sqrt(k) has period 74.

%t cf74Q[n_]:=Module[{s=Sqrt[n]},!IntegerQ[s]&&Length[ContinuedFraction[s][[2]]]==74]; Select[Range[11000],cf74Q] (* _Harvey P. Dale_, Jul 19 2013 *)

%Y Cf. A003285.

%K nonn

%O 1,1

%A _David W. Wilson_