An explicit formula for the sequence defined by the recurrence relation bn = 2bn-1 + 1, with the initial condition b1 = 7 is:

The solution to the recurrence relation: P(n) = 1, for n = 1 P(n) = n-1∑k=1 P(k)P(n-k), for n ≥ 2 is:

Given a recursive function with the recurrence relation T(n) = T(n/3) + 1 for n > 1, and T(1) = 1. What is the total number of function calls (nodes in the recursion tree) made when the function is initially called with n = 27?