Aleksandra started studying how the number of branches in her tree grows over time. Every 1.5 years, the number of branches increases by an addition of 2/7 of the total number of branches. The number of branches be modeled by a function, N, which depends on the amount of time, t (in years).

when aleksandra began the study, her tree had 52 branches.
Write a function that models the number of branches t years since aleksandra began studying her tree.