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 A189508 #12 Apr 20 2015 13:31:21 %S A189508 1,3,21,160,1620,19068,264420,4166880,74011488,1459381440,31674232128 %N A189508 Column 2 of triangle in A189507. %H A189508 Simona Grusea and Anthony Labarre, <a href="http://arxiv.org/abs/1104.3353">The distribution of cycles in breakpoint graphs of signed permutations</a>, arXiv:1104.3353v1 %Y A189508 Cf. A189507. %K A189508 nonn,more %O A189508 1,2 %A A189508 _N. J. A. Sloane_, Apr 23 2011 %E A189508 Added missing term for n=9, _Anthony Labarre_, Feb 14 2013