

A238752


Number of nonisomorphic partial 1differential posets up to rank n.


0




OFFSET

1,5


LINKS

Table of n, a(n) for n=1..10.
P. Byrnes, Structural aspects of differential posets, Ph.D. thesis, University of Minnesota, (2012)
Richard P. Stanley, Fabrizio Zanello, On the rank function of a differential poset, arXiv:1111.4371 [math.CO], 20112012.


EXAMPLE

For n<=4, label nodes with the partitions of n for convenience.
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.


CROSSREFS

Sequence in context: A063443 A133473 A193323 * A099137 A309667 A059586
Adjacent sequences: A238749 A238750 A238751 * A238753 A238754 A238755


KEYWORD

nonn,more


AUTHOR

William J. Keith, Mar 04 2014


STATUS

approved



