The sequence an=an−1+an−2a_n = a_{n-1} + a_{n-2}an=an−1+an−2 with a0=0,a1=1a_0=0, a_1=1a0=0,a1=1. What is ∑i=0nai\sum_{i=0}^n a_i∑i=0nai?
an+2−1a_{n+2} - 1an+2−1
an+1−1a_{n+1} - 1an+1−1
an+an+1a_n + a_{n+1}an+an+1
an+2+1a_{n+2} + 1an+2+1