(mathematics) The question as to the value of ∑ₙ₌₁ ᪲1/(n²), the sum of the reciprocals of the squares of the positive integers.

plural of Barten

A round wooden stool used by piano players. It is less stable than the rectangular piano bench. The height can be adjusted by simply spinning the seat clockwise or counterclockwise, respectively.

One who is maimed.