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 A031697 #21 Jul 15 2021 01:45:55 %S A031697 363,1448,3255,5784,9035,13008,17703,23120,29259,36120,43703,52008, %T A031697 61035,70784,81255,92448,104363,117000,130359,137680,144440,152920, %U A031697 159243,174768,191015,207984,225675,244088,263223,283080,303659,314780,324960 %N A031697 Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 19. %C A031697 (19*m)^2 + 2*m for m >= 1 are terms of this sequence (see comment in A031749). The first term that is not of this form is a(20) = 137680. - _Chai Wah Wu_, Jun 19 2016 %H A031697 Charles R Greathouse IV, <a href="/A031697/b031697.txt">Table of n, a(n) for n = 1..10000</a> (first 60 terms from Vincenzo Librandi) %t A031697 Select[Range[350000],!IntegerQ[Sqrt[#]] &&Min[ContinuedFraction[Sqrt[#]][[2]]] == 19&](* _Vincenzo Librandi_, Feb 10 2012 *) %K A031697 nonn %O A031697 1,1 %A A031697 _David W. Wilson_