A263864 Triangle read by rows: T(n,k) (n>=1, k>=1) is the number of posets with n elements whose Hasse diagram has k connected components.
1, 1, 1, 3, 1, 1, 10, 4, 1, 1, 44, 13, 4, 1, 1, 238, 60, 14, 4, 1, 1, 1650, 312, 63, 14, 4, 1, 1, 14512, 2075, 328, 64, 14, 4, 1, 1, 163341, 17316, 2159, 331, 64, 14, 4, 1, 1, 2360719, 186173, 17801, 2175, 332, 64, 14, 4, 1, 1, 43944974, 2594568, 189406, 17885, 2178, 332, 64, 14, 4, 1, 1, 1055019099, 47041877
Offset: 1
Examples
Triangle begins: 1; 1, 1; 3, 1, 1; 10, 4, 1, 1; 44, 13, 4, 1, 1; ...
Links
- Alois P. Heinz, Rows n = 1..16, flattened
- FindStat - Combinatorial Statistic Finder, The number of connected components of the Hasse diagram for the poset.
- Salah Uddin Mohammad, Md. Shah Noor, and Md. Rashed Talukder, An Exact Enumeration of the Unlabeled Disconnected Posets, J. Int. Seq., Vol. 25 (2022), Article 22.5.4.
- Wikipedia, Hasse diagram
- Index entries for sequences related to posets
Extensions
More terms from R. J. Mathar, Jul 12 2020
Comments