If I have a series that replicates the effect of saving with compounding interest in an economic environment with combating inflation such as:
$$a_{yr} = a_{yr-1}*I_n+N*I_F^{yr-1}$$
Where $yr$ is the index of the term of the series (years of compounding), and $I_n$ and $I_F^{yr-1}$ are variable integers (representing a constant interest rate and compounded constant inflation rate respectively) , how can I find the value of the $yr$ th term?