A377922 Number of polyhedral orientations with n inner vertices.

0, 0, 0, 1, 0, 3, 4, 15, 39, 122, 375, 1212, 3980, 13413, 45966, 160295, 566985, 2032110, 7368334, 27000759, 99891654, 372788553, 1402339329, 5313959388, 20272563265, 77822173758, 300473023929, 1166377045666, 4550358858954, 17835405078273, 70213720795466, 277552814035683

Offset: 0

Author

N. J. A. Sloane, Dec 13 2024

Keywords

• nonn

Comments

a(n) is also the number of combinatorial types of corner polyhedra with n+3 flats, and the number of weak equivalence classes of tricolored contact-systems with n+3 curves. - Éric Fusy, Dec 14 2024

Links

• Éric Fusy, E. Narmanli, and G. Schaeffer, Enumeration of corner polyhedra and 3-connected Schnyder labelings, arXiv preprint arXiv:2202.09172 [math.CO], 2022-2023. See p_n.

Crossrefs

Cf. A001181, A377920, A377921, A377923.

Extensions

a(13) onwards from Éric Fusy, Dec 14 2024