A349401 Number of unlabeled disconnected posets with n elements.

0, 0, 1, 2, 6, 19, 80, 395, 2487, 19890, 206565, 2804453, 49872647, 1158843214, 35049606566, 1374685228988, 69690886873398, 4554367168841547

Offset: 0

Author

Salah Uddin Mohammad, Nov 15 2021

Keywords

• nonn
• more

Links

• Gunnar Brinkmann and Brendan D. McKay, Posets on up to 16 points.
• 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. A000112, A000608, A342500.

Formula

a(n) = A000112(n) - A000608(n).