A379608 Number of unlabeled Riordan posets with n elements.

1, 2, 5, 11, 33, 74, 144, 232, 639

Offset: 1

Author

Salah Uddin Mohammad, Dec 27 2024

Keywords

• nonn
• more

Comments

Posets associated to binary Riordan matrices are called Riordan posets.

Examples

			For example, all the posets up to 3 elements are Riordan posets.
		

Links

• G. S. Cheon et al., Riordan posets and associated incidence matrices, Linear Algebra and its Applications, 632 (2022), 308-331.

Crossrefs

Cf. A000112, A000608, A349401

Extensions

a(9) from Salah Uddin Mohammad, Jun 28 2025