Show that for the sequence defined by ` a_(n) = (n -1) (n-2) ` ,the first two terms are zero and its fifth term is 12 .

Explanation

To solve the problem, we need to show two things about the sequence defined by \( a_n = (n - 1)(n - 2) \):

1. The first two terms are zero.
2. The fifth term is 12.

Let's go through the steps:

### Step 1: Calculate the first term \( a_1 \)
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