It's well-known that the eigenvalues of the Clement-Kac-Sylvester tridiagonal matrix

$$\begin{pmatrix} 0 & n-1 & 0 & \dots & 0 \\\ 1 & 0 & n-2 & \dots & 0\\\ 0 & 2 & 0 & \dots & 0 \\\ \vdots & \vdots & \vdots & \ddots & 1 \\\ 0 & 0 & 0 & n-1 & 0 \end{pmatrix}$$

are $\pm (n), \pm (n-2), ..., (\pm1 \; or \; 0)$. Please refer to Regarding a Paper by Paul.A Clement on Tridiagonal Matrices and https://math.stackexchange.com/questions/405670/regarding-a-paper-by-paul-a-clement-on-tridiagonal-matrices for details.

My question is do we know the eigenvalues of the leading principal submatrix of the Clement-Kac-Sylvester tridiagonal matrix $(1<r\le n/2)$:

$$\begin{pmatrix} 0 & n-1 & 0 & ... & 0 \\\ 1 & 0 & n-2 & & ... \\\ 0 & 2 & 0 & ... & 0 \\\ ... & & ... & & n-r+1 \\\ 0 & ... & 0 & r-1 & 0 \end{pmatrix}$$

or do we have any lower/upper bound on the eigenvalues of this submatrix.