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 A138668 #2 Mar 30 2012 18:35:47 %S A138668 100,301,226,305,341,770,370,876,1232,1800,3451,2044,6816,2666,5876, %T A138668 4459,44982,67082,8350,12840,20724,23571,15840,17100,23001,18190, %U A138668 31093,27756,30176,54245,97019,24708,21582,22584,33429,61201,87814,610305 %N A138668 Values of y in solutions (x,y,z) to the Diophantine equation x^3-x^2+y^3-y^2=z^3-z^2, with 1<x<y<z arranged in order of increasing x. %C A138668 A045991(y)=A045991(z)-A045991(x), x=A138667(n) and z=A138669(n). %Y A138668 Cf. A138667, A138669, A045991. %K A138668 nonn %O A138668 1,1 %A A138668 _Manuel Valdivia_, Apr 17 2008