A222069 Decimal expansion of (1/30)*2^(1/2)*Pi^2.

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

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, "Sphere Packings, Lattices and Groups", Springer, 3rd. ed., 1998. See p. xix.

Links

Table of n, a(n) for n=0..95.

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.

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

N. J. A. Sloane and Andrey Zabolotskiy, Table of maximal density of a packing of equal spheres in n-dimensional Euclidean space (some values are only conjectural).

Index entries for transcendental numbers

Example

.46525761330925863561050406241129368599465775139653615774...

Mathematica

RealDigits[(Sqrt[2] Pi^2)/30, 10, 120][[1]] (* Harvey P. Dale, Nov 07 2021 *)

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, A260646.

Sequence in context: A308716 A021219 A200127 * A274318 A256682 A303404

Adjacent sequences: A222066 A222067 A222068 * A222070 A222071 A222072

Keyword

nonn,cons

Author

N. J. A. Sloane, Feb 10 2013

Status

approved