Expected value of \(n^q\) when \(n\) follows a Poisson distribution of parameter \(n\).
e_n_q(n, q)
A vector of the same length as n containing the transformed values.
The expectation of \(n^q\) when \(n\) follows a Poisson distribution was derived by Grassberger1988;textualdivent.
It is computed using the beta function. Its value is 0 for \(n-q+1<0\), and close to 0 when \(n=q\), which is not a correct estimate: it should not be used when \(q > n\).