A393722 - OEIS

%I #13 Jul 21 2026 11:13:37

%S 1,1,1,3,4,12,27,82,224,708,2158,6950,22315,73221,241386,804944,

%T 2699671,9121604,30986147,105843040,363233296,1252126688

%N Number of free polyominoes in the {3,8} tessellation of the hyperbolic plane.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Order-8_triangular_tiling">Order 8 triangular tiling</a>.

%o (C) // See A393739.

%Y Cf. A330659, A000207.

%K nonn,more,changed

%O 1,4

%A _John Mason_, Érika Roldán, and Rosemberg Toalá-Enríquez, Feb 26 2026

%E a(19)-a(22) from _Ed Wynn_, Jul 20 2026