A331141 Number of symmetrically inequivalent coincidence rotations of index n in lattice A_4.

1, 5, 10, 20, 30, 50, 50, 80, 90, 150, 144, 200, 170, 250, 300, 320, 290, 450, 400, 600, 500, 720, 530, 800, 750, 850, 810, 1000, 900, 1500, 1024, 1280, 1440, 1450, 1500, 1800, 1370, 2000, 1700, 2400, 1764, 2500, 1850, 2880, 2700, 2650, 2210, 3200, 2450

Offset: 1

Author

N. J. A. Sloane, Jan 12 2020

Keywords

• nonn
• mult

Comments

The overall number of coincidence rotations is 120 times higher. Some symmetrically distinct rotations generate the same coincidence site lattices, hence a(n) >= A331142(n). - Andrey Zabolotskiy, Jan 29 2020

Links

• Michael Baake and Peter Zeiner, Coincidences in 4 dimensions, Phil. Mag. 88 (2008), 2025-2032; arXiv:0712.0363 [math.MG]. See end of Section 3.
• Index entries for sequences related to A_4 lattice

Crossrefs

Cf. A031360, A031361, A331139, A331140, A331142.

Extensions

Name corrected and terms a(12) and beyond added by Andrey Zabolotskiy, Jan 29 2020