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 A031671 #14 Aug 18 2021 00:10:32 %S A031671 85313,85898,142210,291769,392101,394609,395866,504389,630797,633977, %T A031671 764317,771325,916378,927898,1078069,1086389,1090561,1098929,1277629, %U A031671 1282153,1460105,1469785,1474637,1479497,1662482,1665061,1667642 %N A031671 Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 83. %Y A031671 Subsequence of A003814. %K A031671 nonn %O A031671 1,1 %A A031671 _David W. Wilson_ %E A031671 First term 6890 removed by _Georg Fischer_, Jun 16 2019