Write the general formula for the geometric sequence with a1 = 3 and r = 2.

1. Identify the first term \(a_1\) which is 3. a_1 = 3
2. Identify the common ratio \(r\) which is 2. r = 2
3. For a geometric sequence, the general formula is given by: a_n = a_1 \times r^{n-1}
4. Substitute the values \(a_1 = 3\) and \(r = 2\): a_n = 3 \times 2^{n-1}

Answer: a_n = 3 \times 2^{n-1}