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 A051971 #7 Sep 21 2021 06:13:21 %S A051971 70,105,111,114,178,183,187,267,273,303,371,374,407,418,470,498,518, %T A051971 545,551,590,602,618,642,803,805,822,923,1005,1007,1034,1118,1167, %U A051971 1173,1178,1202,1581,1605,1623,1653,1707,1749,1790,2103,2109,2147 %N A051971 Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 6. %D A051971 R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A3. %H A051971 Georg Fischer, <a href="/A051971/b051971.txt">Table of n, a(n) for n = 1..79</a> %Y A051971 Cf. A051966-A051989. %K A051971 nonn,fini,full %O A051971 1,1 %A A051971 _N. J. A. Sloane_, Jan 04 2000