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 A134221 #4 Mar 31 2012 10:22:05 %S A134221 12,15,28,44,63,68,101,121,128,148,168,197,198,204,208,220,232,248, %T A134221 269,294,337,343,346,350,369,404,409,443,481,485,492,540,556,561,575, %U A134221 618,640,656,659,701,702,716,740,757,768,775,785,804,829,850,857,868,885 %N A134221 Values n for which integer solutions of Mordell curve y^2=x^3+n have 2 different values of x (or equivalently of nonnegative y). %C A134221 Union of A179147 and A179148. %F A134221 Numbers n such that A134108(n) = Floor((A081119(n)+1)/2) = 2. %Y A134221 Cf. A134108, A134220, A134222, A134223. %K A134221 nonn %O A134221 1,1 %A A134221 _Artur Jasinski_, Oct 14 2007 %E A134221 Edited and extended by _Ray Chandler_, Jul 12 2010