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 A128011 #3 Feb 11 2014 17:06:37 %S A128011 1,4,2,3,4,6,1,8,6,4,3,14,8,2,5,8,10,4,5,6,10,1,12,10,8,6,4,10,3,8,5, %T A128011 12,2,7,5,8,14,3,10,7,4,14,5,26,17,6,7,10,12,14,23,1,16,14,12,10,8,7, %U A128011 6,16,5,14,4,7,10,16,3,14,8,5,12,7,2 %N A128011 Denominators of rational-valued radii of circles given by 3 distinct integer points in the 4-dimensional Euclidean space. %Y A128011 See A128010 for numerators and further information. Cf. A128006, A128007, A128008, A128009. %K A128011 frac,nonn %O A128011 1,2 %A A128011 _Heinrich Ludwig_, Feb 18 2007