I'm reading a cryptography paper and am trying to understand the math behind it. In the paper, one expression is given and refactored into another, equivalent expression. I'm having trouble understanding how the conversion was done.
This expression: $\sqrt[3]{2^{3057} - N*2^{2072} + G}$
is supposed to be equivalent this one: $2^{1019} - (N * 2^{34}/3)$
I understand how the second expression was calculated, except for where $2^{34}$ came from. It looks like everything's being divided by 3, but since the exponent $2072$ doesn't divide perfectly by 3, something was done to it. Can anyone explain?