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 A317970 #6 Aug 29 2018 02:53:55 %S A317970 53,56,61,69,77,88,89,92,93 %N A317970 Positive n such that the ring of algebraic integers O_n in a quadratic number field has class number 1 but is not Euclidean with respect to the norm. %C A317970 The usual symbol in number theory is O_d, not O_n. %H A317970 Erich Kaltofen and Heinrich Rolletschek, <a href="https://doi.org/10.1090/S0025-5718-1989-0982367-2">Computing greatest common divisors and factorizations in quadratic number fields</a>, Mathematics of Computation 53.188 (1989): 697-720. See page 698. %Y A317970 Cf. A014602. %K A317970 nonn,more %O A317970 1,1 %A A317970 _N. J. A. Sloane_, Aug 29 2018