The -ball, denoted , is the interior of a Sphere , and sometimes also called the
-Disk. (Although physicists often use the term ``Sphere'' to mean the solid ball, mathematicians
definitely do not!) Let
denote the volume of an -D ball of Radius . Then

where is the Erf function.

**References**

Freden, E. Problem 10207. ``Summing a Series of Volumes.'' *Amer. Math. Monthly* **100**, 882, 1993.

© 1996-9

1999-05-26