For every , .
How many tuples are there satisfying :
Pick one
Solution
1. We need to find the number of 18-tuples where each and they satisfy the equation:
2. Notice that is a power of 2, and we need to express it as a sum of terms of the form where .
3. We can write as a sum of distinct powers of 2, considering the constraints on . The possible ways to write using the terms are:
4. Each of these expressions represents a unique way to form using the terms with .
5. To count the number of such sets, we observe that each expression corresponds to a unique combination of values. Specifically, each expression involves a different set of indices where and the rest are 0 or -1.
6. The number of such distinct sets is equal to the number of terms in the sequence from to . This sequence has 8 terms.
Conclusion: