A071882 Number of contraction types of n-dimensional parallelohedra.

1, 1, 2, 5, 52, 179372

Offset

0,3

Comments

Or, number of inequivalent Delaunay [Delone] decompositions of R^n.

Sikiric et al. say that actually a(5) = 181394. - Andrey Zabolotskiy, Mar 02 2019

Links

Table of n, a(n) for n=0..5.

Mathieu Dutour Sikirić, Alexey Garber, Achill Schürmann, Clara Waldmann, The complete classification of five-dimensional Dirichlet-Voronoi polyhedra of translational lattices, Acta Crystallographica A72 (2016), 673-683; arXiv:1507.00238 [math.MG], 2015-2016.

P. Engel, The contraction types of parallelohedra in E^5, Acta Cryst. A 56 (2000), 491-496.

M. I. Stogrin, Regular Dirichlet-Voronoi partitions for the second triclinic group, Trudy Matematicheskogo Instituta imeni V. A. Steklova, 123 (1973) = Proceedings of the Steklov Institute of Mathematics, 123 (1973).

Crossrefs

Cf. A071880, A071881.

Sequence in context: A081090 A330282 A071880 * A206848 A081482 A134475

Adjacent sequences: A071879 A071880 A071881 * A071883 A071884 A071885

Keyword

nonn,hard,nice,more

Author

N. J. A. Sloane, Jun 10 2002

Status

approved