A031847 - OEIS

%I #14 Aug 13 2025 09:50:14

%S 23479,31411,47875,70087,79003,88183,127327,132271,135991,168479,

%T 173215,184747,194539,196471,205771,208555,227287,242008,256583,

%U 269107,270751,283624,313847,314375,316543,324719,327611,343312,344259,345119,353659

%N Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 79 ones.

%H Amiram Eldar, <a href="/A031847/b031847.txt">Table of n, a(n) for n = 1..10000</a>

%t cf79Q[n_]:=Module[{s=Sqrt[n]},If[IntegerQ[s],1,Count[ ContinuedFraction[ s][[2]],1]]==79]; Select[Range[360000],cf79Q] (* _Harvey P. Dale_, Dec 14 2015 *)

%K nonn

%O 1,1

%A _David W. Wilson_