A393724 Number of free polyominoes in the {4,8} tessellation of the hyperbolic plane.

1, 1, 2, 5, 16, 60, 261, 1243, 6249, 32638, 174997, 957668, 5326353, 30030598, 171292944, 986985451

Offset

1,3

Links

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

Formula

a(n) = P{p,q}(n) (the number of {p,q} polyominoes of size n) is equal to P{p,oo}(n) for n <= q; also P{p,q}(q+1) = P{p,oo}(q+1) + floor((p-1)/2) - floor((3+q(p-2))/2). In this case, p=4, q=8 and P{p,oo} = A005036.

Crossrefs

Cf. A119611, A332930, A393723, A005036.

Sequence in context: A210668 A279564 A393723 * A005036 A012051 A012159

Adjacent sequences: A393721 A393722 A393723 * A393725 A393726 A393727

Keyword

nonn,more

Author

John Mason, Érika Roldán, and Rosemberg Toalá-Enríquez, Feb 26 2026

Status

approved