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%I #9 Mar 07 2026 05:48:50
%S 1,1,4,21,173,1737,19765,238599,3000689,38861322
%N Number of free polyominoes in the {8,4} tessellation of the hyperbolic plane.
%F 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.
%Y Cf. A393739, A393741, A393742, A393743, A393744, A389937.
%K nonn,more
%O 1,3
%A _John Mason_, Érika Roldán, and Rosemberg Toalá-Enríquez, Mar 02 2026