Practice problem
Which of these is a geometric sequence in recursive form?
an=2n−1a_n = 2^{n-1}an=2n−1
an+1=an+2a_{n+1} = a_n + 2an+1=an+2
an=3na_n = 3nan=3n
an=2an−1a_n = 2a_{n-1}an=2an−1
Type a concept, like “slope” or “photosynthesis”.
