Solve the recurrence relation an=2an−1a_n = 2a_{n-1}an=2an−1 with a0=22a_0 = 22a0=22.
2cdot22n2 \\cdot 22^n2cdot22n
22cdot2n22 \\cdot 2^n22cdot2n
22cdotn222 \\cdot n^222cdotn2
22+2n22 + 2n22+2n