The recurrence $a_n = 1.5a_{n-1} - 0.5a_{n-2}$ has characteristic roots $r_1 = 1$ and $r_2 = 0.5$. Given that the general solution is $a_n = c_1 \cdot 1^n + c_2 \cdot (0.5)^n$ with $c_1 \neq 0$, which best describes the long-term behavior for large $n$?