Hook-content formula

For an integer partition $\lambda$, $s_{\lambda }(1^m)={\prod }_{(i,j)\in \lambda }(m+j-i)/h_{ij}$, where $h_{ij}$ is the cell's hook length. It counts Semistandard Young tableaux of shape $\lambda$ whose entries belong to $\{1,\dots ,m\}$.