Allocating 2^1, 2^2, ..., 2^N is still only allocating 2^(N+1).
Depending on how large N you have, it might very well be worth copying.
Allocating 2^1, 2^2, ..., 2^N is still only allocating 2^(N+1).
Depending on how large N you have, it might very well be worth copying.