A324919 a(n) is the number of I^n-symmetric chains that are not I^k-symmetric for any k dividing n.

2, 2, 12, 28, 80, 180, 476, 1120, 2772, 6640, 16236, 38976

Offset: 1

Author

Felix Fröhlich, Sep 04 2019

Keywords

• nonn
• more

Comments

a(1)-a(12) are the terms of sequence b_n given in row 2 of table I. in Hermisson, Richard, Baake, 1997.

Links

• Joachim Hermisson, Christoph Richard and Michael Baake, A Guide to the Symmetry Structure of Quasiperiodic Tiling Classes, Journal de Physique I, Vol. 7, No. 8 (1997), 1003-1018, DOI:10.1051/jp1:1997200.

Crossrefs

Cf. A129744 (sequence a_n in the paper).