A390195 a(n) is the number of n-celled treelike polyominoes in the {4,5} tessellation of the hyperbolic plane.

1, 1, 2, 5, 15, 54, 214, 928, 4191, 19621, 93874, 457561, 2261678, 11316094, 57202543, 291787443

Offset

1,3

Comments

A treelike polyomino has a tree as its connectedness graph (vertices of this graph correspond to cells and two vertices are connected if the corresponding cells have a common edge). It also has maximal perimeter for its size.

This sequence was calculated in the context of a project in collaboration with Érika Roldán, and Rosemberg Toalá-Enríquez.

Links

Table of n, a(n) for n=1..16.

Crossrefs

Cf. A119611, A131482, A390196.

Sequence in context: A336020 A277175 A056841 * A378939 A185040 A387774

Adjacent sequences: A390192 A390193 A390194 * A390196 A390197 A390198

Keyword

nonn,more

Author

John Mason, Nov 02 2025

Status

approved