Each cut will double the number of slices, so if the recurrence starts with [tex]n=1[/tex], then you have [tex]p(n)=2^{n-1}[/tex].
[tex]p(1)=2^{1-1}=2^0=1[/tex] corresponds to the whole pizza (one "slice").
The first cut gives [tex]p(2)=2^{2-1}=2^1=2[/tex] slices, and so on.
