{\displaystyle P(X_{1}=n_{1}=1)={n \choose 1}n^{-1},\quad P(X_{i}=n_{i}=1\mid X_{i-1}=1)={n-i+1 \choose 1}n^{-1},\quad i=1,\ldots,n.}
{\displaystyle P(X_{1}=n_{1}=1)={n \choose 1}n^{-1},\quad P(X_{i}=n_{i}=1\mid X_{i-1}=1)={n-i+1 \choose 1}n^{-1},\quad i=1,\ldots ,n.}