Poisson factorial moments
= Poisson factorial moments
{c}
If $N$ is Poisson with mean $\lambda$, then $\mathbb{E}[(N)_r]=\lambda^r$; in particular, $\mathbb{E}N=\lambda$ and $\mathbb{E}[N(N-1)]=\lambda^2$.
= Poisson factorial moments
{c}
If $N$ is Poisson with mean $\lambda$, then $\mathbb{E}[(N)_r]=\lambda^r$; in particular, $\mathbb{E}N=\lambda$ and $\mathbb{E}[N(N-1)]=\lambda^2$.