I've been struggling with this and I even asked 2 friends of mine to help me but they couldn't solve it.
Unfortunately, I can't find the function :Z. I hope somebody can help me. thx 4 u time.
The pattern that you are looking for is this
$\displaystyle \{2,4,8,16,.... \}=\{2^1,2^2,2^3,...,2^{64} \}$.
So write this as a sum you get $\displaystyle \sum_{n=1}^{64}2^n$
$\displaystyle \sum_{n=0}^{64}2^n=1+\sum_{n=1}^{64}2^n=\frac{1-2^{64+1}}{1-2}=2^{65}-1$
so we get
$\displaystyle 1+\sum_{n=1}^{64}2^n=2^{65}-1 \iff \sum_{n=1}^{64}2^n=2^{65}-2=36893488147419103230$
This is alot of rice