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 A051978 #7 Sep 21 2021 06:09:04 %S A051978 746,778,1082,1241,1514,1649,2042,2426,3085,3338,3349,4058,4573,4589, %T A051978 4885,5389,7418,7421,8765,9389,9965,10085,12965,14837,16277,17533, %U A051978 19357,21053,22373,25877,30733,31373,31853,36965,38597,39437,40757,53477,69893,81413 %N A051978 Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 13. %D A051978 R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A3. %Y A051978 Cf. A051966-A051989. %K A051978 nonn,fini,full %O A051978 1,1 %A A051978 _N. J. A. Sloane_, Jan 04 2000 %E A051978 a(37) and following from _Georg Fischer_, Sep 21 2021