0 votes 0 votes closed as a duplicate of: Time Complexity What is the tightest upper bound to $T(n) = T(n-1) + 2^n$? $O(n2^n)$ $O(2^n)$ $O(2^{2n})$ None thor asked Jan 10, 2017 • closed Jan 10, 2017 by Prajwal Bhat thor 178 views comment Share Follow See all 0 reply Please log in or register to add a comment.