In mathematics, the fourth powers are given by the expression
- a4 = a × a × a × a
The sequence of fourth powers of integers goes:
1, 16, 81, 256, 625, 1296, 2401, 4096, 6561, 10000, ...
They are also formed by multiplying a number by its cube. Furthermore, they are squares of squares.
The last two digits of a fourth power can be easily shown (for instance, by computing the squares of possible last two digits of square numbers) to be restricted to only twelve possibilities: 00, 01, 16, 21, 25, 36, 41, 56, 61, 76, 81 and 96.