This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A031779 #12 Aug 11 2025 01:21:24
%S A031779 1075,1675,2183,2623,2783,2871,3075,3224,3256,3551,3915,4675,5656,
%T A031779 6808,6815,7599,7663,7987,8299,8399,8695,8995,9271,10672,10855,11395,
%U A031779 11403,11919,12728,13407,14608,14672,15023,15568,15640,15768,16119,16856,17043
%N A031779 Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 11 ones.
%H A031779 Amiram Eldar, <a href="/A031779/b031779.txt">Table of n, a(n) for n = 1..10000</a>
%t A031779 oQ[n_]:=Module[{sqn=Sqrt[n]},!IntegerQ[sqn]&&Count[ ContinuedFraction[ sqn][[2]],1]==11]; Select[Range[20000],oQ] (* _Harvey P. Dale_, Nov 10 2011 *)
%K A031779 nonn
%O A031779 1,1
%A A031779 _David W. Wilson_