A004032 Number of n-dimensional crystal families.
1, 1, 4, 6, 23, 32, 91
Offset: 0
References
- H. Brown, R. Bülow, J. Neubüser, H. Wondratschek and H. Zassenhaus, Crystallographic Groups of Four-Dimensional Space. Wiley, NY, 1978, p. 52.
- N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
Links
- W. Plesken and T. Schulz, Counting crystallographic groups in low dimensions, Experimental Mathematics, Volume 9 Issue 3 (2000), 321-478
- Wikipedia, Space_group
Extensions
a(5)-a(6) from Henry Bottomley, Feb 03 2014