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 A242893 #14 Jun 18 2014 11:54:20 %S A242893 9,9,9,9,18,27,27,36 %N A242893 Beginning with a centrally symmetric 'Sun' configuration of 9 rhombi with rotational symmetry, number of tiles that can be added to the free edges of the tiling. %H A242893 S. Weber, <a href="http://www.jcrystal.com/steffenweber/JAVA/jtiling/jtiling.html">Fourier transform on quasiperiodic point sets</a> (select '9-fold' with 'shift 1/n') %Y A242893 Cf. A242128, A242129, A242888, A242889, A242890, A242891, A242892, A242894, A242895. %K A242893 nonn,more %O A242893 1,1 %A A242893 _Felix Fröhlich_, May 25 2014