1. Let's clarify the problem: you want to know the formula or method to obtain certain numbers, but you haven't specified which numbers or the context. 2. To help you effectively, please provide the numbers or the pattern you are referring to. 3. Generally, to find a formula for a sequence of numbers, we look for patterns such as arithmetic progression, geometric progression, or other functional relationships. 4. For example, if the numbers increase by a constant difference, the formula is for an arithmetic sequence: $$a_n = a_1 + (n-1)d$$ where $a_n$ is the $n$th term, $a_1$ is the first term, and $d$ is the common difference. 5. If the numbers multiply by a constant ratio, the formula is for a geometric sequence: $$a_n = a_1 \times r^{n-1}$$ where $r$ is the common ratio. 6. Please provide the specific numbers or sequence so I can help derive the exact formula for you.