[] N + (n(t-1)) = T
I said this because you have N in the first hour, then after that you have n in t hours, which is equal to T. I subtracted one from t, because for the first hour it produces N.
(I think?)
[] It could also be N + (nt) = T without subtracting 1, but I think subtracting 1 makes sense as I stated above
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather