  We derive the general formulas for a special configuration of the sequential
warped product semi-Riemannian manifold to be Einstein, where the base-manifold
is the product of two manifolds both equipped with a conformal metrics.
Subsequently we study the case in which these two manifolds are conformal to a
$n_1$-dimensional and $n_2$-dimensional pseudo-Euclidean space, respectively.
For the latter case, we prove the existence of a family of solutions that are
invariant under the action of a $(n_1-1)$-dimensional group of transformations
to the case of positive constant Ricci curvature ($\lambda>0$).
