The mobility of Riemannian spaces with respect to conformal mappings onto Einstein spaces

We consider the first lacuna in the distribution of the mobility of $n$-dimensional (pseudo-)Riemannian spaces with respect to conformal mappings onto Einstein spaces. We obtain a tensor characteristic of spaces different from conformally flat ones, for which $r=n-1$; this number is the maximal possible value. Thus, we have found maximally mobile spaces (different from conformally flat ones) with $r=n-1$.