What are the first three terms of the sequence: a1 = 3 and an = 2(an -1)^2? . a. 2, 8, 18. b. 3, 18, 648. c. 3, 32, 50. d. 2, 6, 12, 24.

The first term of the sequence is already given to be 3. Use this value to obtain the second term.
                                     a2 = 2(a1)^2 = 2(3)² = 18
Use the value of the second term to get the third term through the equation,
                                     a3 = 2(a2)² = 2(18)² = 648
Thus, the answer to this item is letter B.