A197467 Number of fixed poly-[4.8^2]-tiles (holes allowed) with n cells (division into triangles is significant).

4, 6, 12, 25, 56, 132, 320, 792, 1976, 4962, 12576, 32140, 82704, 214044, 556576, 1453210, 3808592, 10015134, 26413468, 69844263, 185126524, 491758054, 1308874676, 3490068514, 9321677540, 24935748182, 66798957432

Offset: 1

Author

Joseph Myers, Oct 15 2011

Keywords

• hard
• nonn

References

• Branko Grünbaum and G. C. Shephard, Tilings and Patterns. W. H. Freeman, New York, 1987, Sections 2.7, 6.2 and 9.4.

Links

• Gill Barequet and Minati De, A Lower Bound on the Growth Constant of Polyaboloes on the Tetrakis Lattice, International Computing and Combinatorics Conference (COCOON 2019): Computing and Combinatorics, 13-24.

Crossrefs

Cf. A197465, A197466.

Extensions

a(21) from Johann Peters, Oct 31 2024

a(22)-a(27) from Johann Peters, Dec 16 2024