

A222072


Decimal expansion of (1/384)*Pi^4.


13



2, 5, 3, 6, 6, 9, 5, 0, 7, 9, 0, 1, 0, 4, 8, 0, 1, 3, 6, 3, 6, 5, 6, 3, 3, 6, 6, 3, 7, 6, 8, 3, 6, 2, 2, 7, 2, 1, 2, 8, 3, 2, 2, 5, 4, 3, 5, 5, 9, 5, 1, 6, 1, 8, 9, 8, 8, 1, 9, 7, 5, 5, 0, 4, 9, 4, 7, 1, 5, 7, 6, 9, 4, 1, 8, 8, 2, 0, 8, 2, 3, 4, 1, 1, 7, 7, 5, 6, 9, 5, 9, 2, 3, 8, 3, 5, 9, 1, 8, 1, 0, 1
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OFFSET

0,1


COMMENTS

Conjectured to be density of densest packing of equal spheres in 8 dimensions (achieved for example by the D_8 lattice).
The above conjecture is true (cf. Viazovska, 2017).  Felix Fröhlich, Jan 08 2018


REFERENCES

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


LINKS



FORMULA

Equals Sum_{n>=1} Sum_{k>=n} 1/(2*n  1)^2/(2*k + 1)^2.  Geoffrey Critzer, Nov 03 2013


EXAMPLE

.25366950790104801363656336637683622721283225435595161898819...


MATHEMATICA



PROG



CROSSREFS

Related constants: A020769, A020789, A093766, A093825, A222066, A222067, A222068, A222069, A222070, A222071, A222073, A222074, A222075.


KEYWORD



AUTHOR



STATUS

approved



