How can I express such a product?

Question

I know for example that

$$\prod^{k}_{n=0} a_n = a_0 \cdot a_1 \cdot a_2 \cdot a_3 \cdots a_k$$

But what if I wanted to express $\space 3^k$ as a product?

I know it sounds like a simple question, but this really got me confused for a good thirty minutes.

Answer 1

$$ 3^k = \prod_{n=1}^k 3. $$ $\qquad\qquad\qquad$