Python: Numbers like 2, 5, 8, 11, are called an arithmetic sequence where there is an initial term and a common difference. In our case, the sequence starts at 2 with a common difference of 3. We only look at sequences that have a finite number of terms and we can generally denote it as a, a+d, a+2*d, ..., a+(n-1)*d, where a is the initial term, d is the common difference and n is the number of terms in the series. The sum of such a series is (a + a+(n-1) * d) * n / 2. Write a Python function called sequence_sum that takes three arguments: the initial term, the difference, and the number of terms. This function should return the correct sum of the sequence.