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 A051972 #4 Mar 30 2012 16:48:43 %S A051972 58,202,314,538,685,949,1165,1261,2885,3133,3277,3653,5429,5765,6437, %T A051972 7373,9197,9509,12557,16757,17141,17261,18317,22301 %N A051972 Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 7. %D A051972 R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A3. %Y A051972 Cf. A051966-A051989. %K A051972 nonn,fini,full %O A051972 1,1 %A A051972 _N. J. A. Sloane_, Jan 04 2000