A002395 a(n) is the number of crystal forms in n dimensions.

1, 2, 9, 47

Offset

0,2

Comments

a(3) is 47 or 48 depending on the classification used (whether dome and sphenoid are distinguished). Engel and the International Tables give 47. - Andrey Zabolotskiy, Nov 27 2017

References

P. Engel, "Geometric crystallography", in P. M. Gruber and J. M. Wills, editors, Handbook of Convex Geometry. North-Holland, Amsterdam, Vol. B, pp. 989-1041.

IUCr, The International Tables for Crystallography, Volume A, Table 10.1.2.3 in 2006 edition or Table 3.2.1.3 in 2016 edition.

Links

Table of n, a(n) for n=0..3.

Steven Dutch, The 48 Special Crystal Forms

Online Dictionary of Crystallography, Form

Crossrefs

Sequence in context: A049371 A306725 A032079 * A356142 A042793 A059272

Adjacent sequences: A002392 A002393 A002394 * A002396 A002397 A002398

Keyword

nonn,hard

Author

N. J. A. Sloane

Status

approved