If `X={4^(n)-3n-1:n in N} and {9(n-1):n in N}`, the prove that `X sub Y`.

Explanation

To prove that \( X \subset Y \), we need to show that every element of set \( X \) is also an element of set \( Y \).

### Step 1: Define the sets
Let:
- \( X = \{ 4^n - 3n - 1 : n \in \mathbb{N} \} \)
- \( Y = \{ 9(n - 1) : n \in \mathbb{N} \} \)

### Step 2: Find the first few elements of \( X \)
...