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 A347300 #3 Aug 28 2021 06:37:41 %S A347300 5,17,37,101,197,677 %N A347300 Under Hypothesis(H) (a version of the Generalized Riemann Hypothesis) the only principal real quadratic fields with discriminant d = r^2 + 1 == 1 (mod 4) are the fields Q(sqrt(t)) where t is one of the six numbers listed here. %D A347300 Gilles Lachaud, On real quadratic fields, Bull. Amer. Math. Soc., 17:2 (1987), 307-311. See Theorem 3.2. %Y A347300 Cf. A003173, A003174, A014602, A050950. %K A347300 nonn,fini,full %O A347300 1,1 %A A347300 _N. J. A. Sloane_, Aug 28 2021