A395872 - OEIS

%I #6 May 13 2026 12:11:58

%S 1,1,2,7,25,108,492,2431,12356,65004,349276,1913919,10648905,60053535,

%T 342565090,1973928324

%N Number of oriented polyominoes in the {4,8} tessellation of the hyperbolic plane.

%C For oriented polyominoes, chiral pairs are counted as two.

%H <a href="https://oeis.org/wiki/PF-Non-Euclidean">Wiki page indexing sequences related to non-euclidean polyforms</a>

%e a(n) = P{p,q}(n) (the number of oriented {p,q} polyominoes of size n) is equal to P{p,oo}(n) for n <= q. In this case, P{p,oo} = A005034.

%t (* Cf. A394862 with p=4 and q=8. *)

%Y Cf. A005034, A393724, A394862.

%K nonn,more

%O 1,3

%A _John Mason_, Érika Roldán, and Rosemberg Toalá-Enríquez, May 10 2026