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 A306300 #37 Dec 07 2020 04:24:46 %S A306300 1,5,2,3,13,17,21,6,7,29,33,37,10,41,11,53,14,57,15,61,65,69,73,19,77, %T A306300 85,22,89,23,93,97,101,26,105,109,113,30,31,129,133,34,137,35,141,145, %U A306300 149,38,39,157,161,165,42,43,173,177,181,46,185,47,193,197 %N A306300 Discriminant D of real quadratic number field Q(sqrt(D)) associated with fundamental discriminant d = A003658(n). %H A306300 Amiram Eldar, <a href="/A306300/b306300.txt">Table of n, a(n) for n = 1..10000</a> %H A306300 Britta Habdank-Eichelsbacher, <a href="http://sfb343.math.uni-bielefeld.de/sfb343/preprints/pre95005.ps.gz">Unimodulare Gitter über Reell-Quadratischen Zahlkörpern</a>, Ergänzungsreihe 95-005, Univ. Bielefeld, 1995. See Section 4.2. %F A306300 a(n) = A007913(A003658(n)) = A003658(n) / (A008833(A003658(n))). %Y A306300 Cf. A003658, A007913, A008833. %K A306300 nonn %O A306300 1,2 %A A306300 _N. J. A. Sloane_, Apr 02 2019