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 A238752 #17 Feb 26 2017 03:11:19 %S A238752 1,1,1,1,2,5,35,643,44606,29199636 %N A238752 Number of nonisomorphic partial 1-differential posets up to rank n. %H A238752 P. Byrnes, <a href="http://hdl.handle.net/11299/142992">Structural aspects of differential posets</a>, Ph.D. thesis, University of Minnesota, (2012) %H A238752 Richard P. Stanley, Fabrizio Zanello, <a href="http://arxiv.org/abs/1111.4371">On the rank function of a differential poset</a>, arXiv:1111.4371 [math.CO], 2011-2012. %e A238752 For n<=4, label nodes with the partitions of n for convenience. %e A238752 At n=5, the two possible posets are the Young poset (nodes and covering relations are the partitions of 5) and the poset constructed by covering the partitions (31), (22) and (211) with a common element, then giving each of those partitions another cover, and leaving all other nodes the same. %K A238752 nonn,more %O A238752 1,5 %A A238752 _William J. Keith_, Mar 04 2014