2018 AMC 10A Problems/Problem 18
How many nonnegative integers can be written in the form where for ?
Solution
This looks like balanced ternary, in which all the integers with absolute values less than are represented in digits. There are 8 digits. Plugging in 8 into the formula gives a maximum bound of , which means there are 3280 positive integers, 0, and 3280 negative integers. Since we want all nonnegative integers, there are integers or .