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 A051969 #4 Mar 30 2012 16:48:43 %S A051969 34,55,78,95,119,138,155,174,194,205,215,222,266,287,299,305,318,335, %T A051969 377,395,429,482,527,623,755,782,861,885,1022,1055,1205,1405,1469, %U A051969 1965,2013,2093,2222,2301,2373,2877,3005,3237,3597,3813,4893 %N A051969 Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 4. %D A051969 R. A. Mollin, Quadratics, CRC Press, 1996, Appendix A, Table A3. %Y A051969 Cf. A051966-A051989. %K A051969 nonn,fini %O A051969 1,1 %A A051969 _N. J. A. Sloane_, Jan 04 2000