+1088 A sequence a_1, a_2, a_3, \dots of positive integers has the following properties:
* The first three terms are in geometric progression.
* The second, third, and fourth terms are in arithmetic progression.
* In general, for all $i\ge1$, the terms $a_{2i - 1}$, $a_{2i}$, $a_{2i + 1}$ are in geometric progression, and the terms $a_{2i}$, $a_{2i + 1}$, and $a_{2i + 2}$ are in arithmetic progression.
If a_1 = 1 and $a_2 = 2, then find a_5.
