Delayed Pad é–Lanczos approximant

This chapter deals with delayed Pad é–Lanczos approximant. Here, Qn(s)(u) and Pn(s)(u) are delayed Lanczos polynomials of the first and second kind, respectively. They can be defined via their recursions similar to their non-delayed counterparts. The degrees of the polynomials pn(s)(u) and Qn(s)(u) are n - 1 and n, respectively. The recursion and for these two latter polynomials are exactly the same, except for the different initializations.