Sobolev orthogonal polynomials: Connection formulae

This contribution aims to obtain several connection formulae for the polynomial sequence, which is orthogonal with respect to the discrete Sobolev inner product $$\langle f, g\rangle_n=\langle {\bf u}, fg\rangle+ \sum_{j=1}^M \mu_{j} f^{(\nu_j)}(c_j) g^{(\nu_j)}(c_j),$$ where ${\bf u}$ is a classical linear functional, $c_j\in \mathbb R$, $\nu_j\in \mathbb N_0$, $j=1, 2,...., M$. The Laguerre case will be considered.