

A081314


Order of symmetry groups of n points on 3dimensional sphere with the volume enclosed by their convex hull maximized.


3



24, 12, 48, 20, 8, 12, 16, 4, 120, 4, 24, 12, 24, 4, 6, 2, 8, 2, 4, 6, 4, 2, 2, 20
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OFFSET

4,1


COMMENTS

If more than one configuration with maximal volume exists for a given n, the one with the largest symmetry group is chosen. Berman and Hanes give optimality proofs for n<=8. Higher terms are only conjectures. An independent verification of the results by Hardin, Sloane and Smith has been performed by Pfoertner in 1992 for n<28. An archive of the results with improvements for n=23,24 added in 2003 is available at link. A conjectured continuation of the sequence starting with n=28 is: 12,6,2,6,120,2,4,4,2,20,4,12,24,12,20,4,8,2,2,2,4,1,24


LINKS

Table of n, a(n) for n=4..27.
Joel D. Berman and Kitt Hanes, Volumes of Polyhedra Inscribed in the Unit Sphere in E3. Mathematische Annalen 188, 7884 (1970)
R. H. Hardin, N. J. A. Sloane and W. D. Smith, Maximal Volume Spherical Codes
Hugo Pfoertner, Maximal Volume Arrangements of Points on Sphere. Visualizations for n<=21.
Hugo Pfoertner, Maximal Volume Arrangements: Archive


EXAMPLE

a(12)=120 because the order of the point group of the icosahedron, which is also the best known arrangement for the maximal volume problem is 120. a(7)=20 because the double 7pyramid proved optimal by Berman and Hanes has dihedral symmetry order 20.


CROSSREFS

Number of distinct edges in convex hull: A081366. Symmetry groups for Tammes problem: A080865.
Sequence in context: A079341 A080865 A040555 * A119872 A002550 A075605
Adjacent sequences: A081311 A081312 A081313 * A081315 A081316 A081317


KEYWORD

hard,nonn


AUTHOR

Hugo Pfoertner, Mar 19 2003


STATUS

approved



