A057649 - OEIS

A057649

Nearest integer to ratio of volume of n-dimensional cube of side 2 to volume of n-dimensional ball of radius 1.

1, 1, 1, 2, 3, 6, 12, 27, 63, 155, 402, 1087, 3068, 8996, 27340, 85905, 278485, 929713, 3191201, 11245603, 40631628, 150342633, 569071745, 2201355134, 8694775795, 35035655103, 143916920872, 602218550964, 2565370007349, 11118142868084, 48994958103507

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OFFSET

0,4

REFERENCES

J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 9.

LINKS

Table of n, a(n) for n=0..30.

FORMULA

a(n) = 2^n*GAMMA(n/2+1)/Pi^(n/2).

CROSSREFS

Cf. A072168, A072345, A072346.

Sequence in context: A108915 A082395 A061343 * A104872 A006082 A122889

Adjacent sequences: A057646 A057647 A057648 * A057650 A057651 A057652

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Sep 06 2003

STATUS

approved