A031821 - OEIS

%I #10 Aug 12 2025 02:40:33

%S 6031,18643,38263,42559,44323,49039,60131,75067,89464,93304,93328,

%T 94051,94119,97399,98375,99299,110171,119848,119995,128927,132355,

%U 143464,144055,147911,148843,152227,156871,158107,162328,164755,166071,167587

%N Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 53 ones.

%H Amiram Eldar, <a href="/A031821/b031821.txt">Table of n, a(n) for n = 1..10000</a>

%t q[k_] := Module[{c = ContinuedFraction[Sqrt[k]]}, Length[c] == 2 && Count[c[[2]], 1] == 53]; Select[Range[50000], q] (* _Amiram Eldar_, Aug 12 2025 *)

%K nonn

%O 1,1

%A _David W. Wilson_