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A222067 Decimal expansion of 1/(8*sqrt(3)). 12
7, 2, 1, 6, 8, 7, 8, 3, 6, 4, 8, 7, 0, 3, 2, 2, 0, 5, 6, 3, 6, 4, 3, 5, 9, 7, 5, 6, 2, 7, 4, 4, 6, 8, 1, 9, 5, 5, 9, 5, 0, 2, 1, 8, 9, 0, 8, 7, 6, 5, 8, 5, 9, 5, 0, 2, 3, 2, 5, 2, 9, 0, 8, 1, 0, 4, 9, 7, 2, 0, 9, 0, 3, 7, 8, 6, 6, 6, 6, 8, 2, 1, 1, 7, 1, 4, 4, 2, 4, 4, 4, 8, 2, 1, 8, 6, 9, 0, 6, 5, 3, 1, 5, 1 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Conjectured to be center density of densest packing of equal spheres in six dimensions (achieved for example by the E_6 lattice).

REFERENCES

J. H. Conway and N. J. A. Sloane, What are all the best sphere packings in low dimensions?, Discr. Comp. Geom., 13 (1995), 383-403.

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer, 3rd. ed., 1998. See p. xix.

LINKS

Table of n, a(n) for n=0..103.

G. Nebe and N. J. A. Sloane, Home page for E_6 lattice

N. J. A. Sloane, Table of maximal density of a packing of equal spheres in n-dimensional Euclidean space (for n>3 the values are only conjectural).

EXAMPLE

.7216878364870322056364359756274468195595021890876585950232529...

PROG

(PARI) 1/sqrt(192) \\ Charles R Greathouse IV, Oct 31 2014

CROSSREFS

Related constants: A020769, A020789, A093766, A093825, A222066, A222068, A222069, A222070, A222071, A222072, A222073, A222074, A222075.

Sequence in context: A133362 A317925 A010140 * A154020 A060991 A120455

Adjacent sequences:  A222064 A222065 A222066 * A222068 A222069 A222070

KEYWORD

nonn,cons

AUTHOR

N. J. A. Sloane, Feb 10 2013

STATUS

approved

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Last modified March 29 21:32 EDT 2020. Contains 333117 sequences. (Running on oeis4.)