\documentclass[11pt,a4paper]{article}
\begin{document}
\[\bar n^*_j(s)=\frac{\left\{s\sum^k_{i=1}n_i(0)p^*_{i,k+1}(s)+M^*(s)\right\}\sum^k_{i=1}p_(0i)p^*{ij}(s)}{1-s\sum^k_{i=1}p_{0i}p^*_{i,k+1}(s)}+\sum^k_{i=1}n_i(0)p^*_{ij}(s),\quad (j=1,2,\dots,k).\]
\end{document}




.
