OFFSET
0,2
COMMENTS
Although there are infinitely many inequivalent vertices with local eight-fold symmetry in the tiling, there is (presumably) a unique vertex with global eight-fold symmetry, which makes this sequence well-defined. - N. J. A. Sloane, Oct 20 2018
REFERENCES
F. P. M. Beenker, Algebraic theory of non-periodic tilings of the plane by two simple building blocks: a square and a rhombus, Eindhoven University of Technology 1982, TH-Report, 82-WSK04.
A. Bellos and E. Harriss, Patterns of the Universe: A Coloring Adventure in Math and Beauty, unnumbered pages, 2015. See illustration about halfway through the book.
LINKS
Rémy Sigrist, Table of n, a(n) for n = 0..985
M. Baake, U. Grimm, P. Repetowicz and D. Joseph, Coordination sequences and critical points, arXiv:cond-mat/9809110 [cond-mat.stat-mech], 1998; in: S. Takeuchi and T. Fujiwara, Proceedings of the 6th International Conference on Quasicrystals - Yamada Conference XLVII, World Scientific Publishing, 1998, ISBN 981-02-3343-4, pp 124-127. See for example Table 2.
Rémy Sigrist, Illustration of the first terms
Rémy Sigrist, C++ program for A303981
N. J. A. Sloane, Coordination Sequences, Planing Numbers, and Other Recent Sequences (II), Experimental Mathematics Seminar, Rutgers University, Jan 31 2019, Part I, Part 2, Slides. (Mentions this sequence)
Tilings Encyclopedia, Ammann-Beenker
Wikipedia, Ammann-Beenker tiling
PROG
(C++) See Links section.
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, May 04 2018
STATUS
approved