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 A349649 #10 Dec 29 2021 02:23:56 %S A349649 12,21,24,28,33,44,56,57,60,69,76,77,88,92,93,105,120,124,129,133,136, %T A349649 140,141,152,156,161,165,168,172,177,184,188,201,204,205,209,213,217, %U A349649 220,221,236,237,248,249,253,264,268,273,280,284,285,301,305,309,312,316 %N A349649 Discriminants of real quadratic fields whose fundamental unit has norm 1. %D A349649 D. A. Buell, Binary Quadratic Forms, Springer-Verlag, NY, 1989, pp. 92-93. %D A349649 Paulo Ribenboim, My Numbers, My Friends: Popular Lectures on Number Theory, Springer-Verlag, NY, 2000, p. 151. %H A349649 <a href="/index/Qua#quadfield">Index entries for sequences related to quadratic fields</a> %o A349649 (PARI) isok(D) = isfundamental(D) && norm(quadunit(D))==1; %Y A349649 Cf. A003658, A003653 (discriminants of real quadratic fields whose fundamental unit has norm -1). %Y A349649 Cf. A003656, A327297 (a subsequence). %K A349649 nonn %O A349649 1,1 %A A349649 _Arkadiusz Wesolowski_, Nov 23 2021