What is the closed form of an=an−1+2an−2a_n = a_{n-1} + 2a_{n-2}an=an−1+2an−2 with a0=1,a1=1a_0 = 1, a_1 = 1a0=1,a1=1?
23(−1)n+132n\frac{2}{3} (-1)^n + \frac{1}{3} 2^n32(−1)n+312n
13(−1)n+232n\frac{1}{3} (-1)^n + \frac{2}{3} 2^n31(−1)n+322n
(−1)n+2n(-1)^n + 2^n(−1)n+2n
2(−1)n−2n2(-1)^n - 2^n2(−1)n−2n