A349367 Number of n-element unlabeled disconnected N-free posets.

0, 1, 2, 6, 18, 65, 241, 984, 4250, 19590, 95484, 491459, 2660030, 15100494, 89648378

Offset: 1

Author

Salah Uddin Mohammad, Nov 15 2021

Keywords

• nonn
• more

Links

• Soheir M. Khamis, Height counting of unlabeled interval and N-free posets, Discrete Math. 275 (2004), no. 1-3, 165-175.
• 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.

Crossrefs

Cf. A202182, A202180.

Formula

a(n) = A202182(n) - A202180(n).