Hereditary Representation
The representation of a number as a sum of powers of a base b, followed by expression of each of the exponents as a sum of powers of b, etc., until the process stops. For example, the hereditary representation of 266 in base 2 is 266 | = | 2^8 + 2^3 + 2 | = | 2^(2^(2 + 1)) + 2^(2 + 1) + 2.