On the number of equivalence classes of invertible Boolean functions under action of permutation of variables on domain and range

Let $V_n$ be the number of equivalence classes of invertible maps from $\{0,1\}^n$ to $\{0,1\}^n$, under action of permutation of variables on domain and range. So far, the values $V_n$ have been known for $n\le 6$. This paper describes the procedure by which the values of $V_n$ are calculated for $n\le 30$.