Let $P(n)$ denotes the number of partitions of $n$. Can we deduce from the Theorem 1.1 and Theorem 1.3 of split etension, that the number of isomorphism classes of splits extensions of $( \mathbb{Z} / p \mathbb{Z} )^n$ by $\mathbb{Z} / p \mathbb{Z} $ is $P(n)-1$ ?.

Any help would be appreciated so much. Thank you all.