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 A051967 #6 Mar 30 2012 16:48:43 %S A051967 15,30,35,39,42,51,66,87,102,110,123,143,146,165,182,203,221,230,258, %T A051967 285,327,357,402,447,635,645,678,741,843,902,957,1085,1245,1298,1517, %U A051967 1533,2037,2045,2085,2397,2613,4245,4277,4773,5645,5957,6573,8333 %N A051967 Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 2. %D A051967 R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A3. %H A051967 R. A. Mollin, H. C. Williams, <a href="http://dx.doi.org/10.1090/S0025-5718-1992-1136224-1">On real quadratic fields of class number two</a>, Math. Comp. 59 (1992) 625-632. %Y A051967 Cf. A051966-A051989. %K A051967 nonn,fini,full %O A051967 1,1 %A A051967 _N. J. A. Sloane_, Jan 04 2000