A031691 - OEIS

%I #15 Jul 14 2021 06:01:41

%S 171,680,1527,2712,4235,6096,8295,10832,13707,16920,20471,24360,28587,

%T 31003,33152,36127,38055,43296,48875,54792,61047,67640,71330,74571,

%U 81840,89447,97392,105675,106326,114296,114973,123255,123958,128219,132552

%N Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 13.

%H Charles R Greathouse IV, <a href="/A031691/b031691.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[Range[200000],!IntegerQ[Sqrt[#]]&&Min[ContinuedFraction[Sqrt[#]][[2]]]==13&] (* _Vincenzo Librandi_, Feb 06 2012 *)

%K nonn

%O 1,1

%A _David W. Wilson_