Negative base

A negative base is a positional number system where the radix b is a negative integer such that -2 ≥ b. Each digit can have a value v of 0 ≤ v ≤ |b| - 1.

Value of a number
The value of a number in a negative base is determined, like in a positive base, by multiplying the value of the digit by the appropriate power of the base. With a negative base, this means that powers where the exponent is an even number will yield positive values, while odd powers will yield negative numbers. As such, an advantage of negative bases is that, while unintuitive, they can express negative and positive numbers without a sign (- or +).

List of negative bases
The name of a negative base is derived by adding a nega- prefix to the name of the standard positional number system. Negative bases have very little practical usage and are generally regarded as a curiosity.