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 $$⟨f,g{⟩}_n=⟨\mathbf{u},fg⟩+\sum _{j=1}^M{\mu }_j{f}^{({\nu }_j)}(c_j)g^{({\nu }_j)}(c_j),$$ where $\mathbf{u}$ is a classical linear functional, $c_j\in \mathbb{R}$, ${\nu }_j\in {\mathbb{N}}_0$, $j=1,2,\mathrm{.}\mathrm{.}\mathrm{.}\mathrm{.},M$. The Laguerre case will be considered.