A sequence is defined by a0=2a_0 = 2a0=2, a1=5a_1 = 5a1=5, and an=3an−1−2an−2a_n = 3a_{n-1} - 2a_{n-2}an=3an−1−2an−2 for n≥2n \geq 2n≥2. Find the closed-form formula for ana_nan.
an=3⋅2n−1a_n = 3 \cdot 2^n - 1an=3⋅2n−1
an=2n+3a_n = 2^n + 3an=2n+3
an=4⋅2n−3a_n = 4 \cdot 2^n - 3an=4⋅2n−3
an=2n+1+1a_n = 2^{n+1} + 1an=2n+1+1