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 A193938 #19 Jun 14 2020 09:42:40 %S A193938 1,2,6,24,118,675,4333,30464,230615,1856336,15738672,139509303, %T A193938 1285276242,12248071935,120255584181,1212503440774,12519867688928, %U A193938 132079067871313,1420723274988736,15554956521285848 %N A193938 3-nonnesting permutations. %C A193938 Also the number of 3-noncrossing permutations. %H A193938 Sophie Burrill, Sergi Elizalde, Marni Mishna and Lily Yen, <a href="http://arxiv.org/abs/1108.5615">A generating tree approach to k-nonnesting partitions and permutations</a>, arXiv preprint arXiv:1108.5615 [math.CO], 2011-2014. %H A193938 S. Corteel, <a href="http://dx.doi.org/10.1016/j.aam.2006.01.006">Crossings and alignments of permutations</a>, Adv. Appl. Math 38 (2007) 149-163. %Y A193938 Cf. A193935, A193936, A193937. %K A193938 nonn,more %O A193938 1,2 %A A193938 _Lily Yen_, Aug 09 2011