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A133491
Order of the symmetry group of the (in some cases conjectural) minimal-energy configuration of n identical charged particles confined to the surface of a sphere.
2
12, 24, 12, 48, 20, 16, 12, 16, 4, 120, 4
OFFSET
3,1
COMMENTS
a(0), a(1) and a(2) are all infinite, because their symmetry groups are continuous (they contain rotations with arbitrary angles). Actual symmetry groups: 3 D_{3h}, 4 T_{d}, 5 D_{3h}, 6 O_{d}, 7 D_{5h}, 8 D_{4d}, 9 D_{3h}, 10 D_{4h}, 11 D_{1h}, 12 I_{d}, 13 D_{1h}.
EXAMPLE
a(3)=12 because the minimal-energy configuration of 3 charged particles on a sphere is an equilateral triangle on the equator, which has symmetry group D_3h of order 12.
CROSSREFS
Sequence in context: A072822 A239656 A059161 * A075606 A183192 A117320
KEYWORD
nonn,more
AUTHOR
Keenan Pepper, Nov 30 2007
STATUS
approved