A197461 Number of fixed poly-[3.6.3.6]-tiles (holes allowed) with n cells (division into rhombi is significant).

3, 6, 14, 36, 99, 281, 816, 2415, 7260, 22074, 67743, 209552, 652566, 2043672, 6431715, 20328504, 64494678, 205303537, 655493697, 2098500135, 6734498816, 21660087087, 69805491342

Offset: 1

Author

Joseph Myers, Oct 15 2011

Keywords

• hard
• more
• nonn

References

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

Crossrefs

Cf. A197459, A197460.

Extensions

a(18)-a(22) from Aaron N. Siegel, May 16 2022

a(23) from Johann Peters, Dec 16 2024