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A071882 Number of contraction types of n-dimensional parallelohedra. 4
1, 1, 2, 5, 52, 179372 (list; graph; refs; listen; history; text; internal format)
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
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
Sequence in context: A081090 A330282 A071880 * A206848 A081482 A134475
KEYWORD
nonn,hard,nice,more
AUTHOR
N. J. A. Sloane, Jun 10 2002
STATUS
approved

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Last modified April 12 06:13 EDT 2024. Contains 371623 sequences. (Running on oeis4.)