A393740 Number of free polyominoes in the {8,4} tessellation of the hyperbolic plane.

1, 1, 4, 21, 173, 1737, 19765, 238599, 3000689, 38861322

Offset

1,3

Links

Table of n, a(n) for n=1..10.

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=8, q=4 and P{p,oo} = A389937.

Crossrefs

Cf. A393739, A393741, A393742, A393743, A393744, A389937.

Sequence in context: A078670 A317104 A163948 * A383379 A278993 A306067

Adjacent sequences: A393737 A393738 A393739 * A393741 A393742 A393743

Keyword

nonn,more

Author

John Mason, Érika Roldán, and Rosemberg Toalá-Enríquez, Mar 02 2026

Status

approved