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A222069 Decimal expansion of (1/30)*2^(1/2)*Pi^2. 12
4, 6, 5, 2, 5, 7, 6, 1, 3, 3, 0, 9, 2, 5, 8, 6, 3, 5, 6, 1, 0, 5, 0, 4, 0, 6, 2, 4, 1, 1, 2, 9, 3, 6, 8, 5, 9, 9, 4, 6, 5, 7, 7, 5, 1, 3, 9, 6, 5, 3, 6, 1, 5, 7, 7, 4, 3, 5, 6, 6, 4, 4, 4, 5, 0, 1, 3, 2, 7, 1, 8, 4, 1, 8, 8, 8, 7, 1, 8, 1, 4, 3, 1, 1, 1, 6, 0, 0, 8, 9, 1, 5, 4, 0, 5, 4 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Conjectured to be density of densest packing of equal spheres in five dimensions (achieved for example by the D_5 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..95.

G. Nebe and N. J. A. Sloane, Home page for D_5 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

.46525761330925863561050406241129368599465775139653615774...

PROG

(PARI) Pi^2/sqrt(450) \\ Charles R Greathouse IV, Oct 31 2014

CROSSREFS

Related constants: A020769, A020789, A093766, A093825, A222066, A222067, A222068, A222070, A222071, A222072, A222073, A222074, A222075.

Sequence in context: A019123 A021219 A200127 * A274318 A256682 A002245

Adjacent sequences:  A222066 A222067 A222068 * A222070 A222071 A222072

KEYWORD

nonn,cons

AUTHOR

N. J. A. Sloane, Feb 10 2013

STATUS

approved

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Last modified August 19 19:25 EDT 2017. Contains 290821 sequences.