Which functions satisfy the recurrence an=2an−1a_n = 2a_{n-1}an=2an−1?
an=3⋅2na_n = 3 \cdot 2^nan=3⋅2n
an=2n+1a_n = 2^{n+1}an=2n+1
an=n2a_n = n^2an=n2
an=3⋅2na_n = 3 \cdot 2^nan=3⋅2n and an=2n+1a_n = 2^{n+1}an=2n+1