Resumen de Extensions of Drummond's process for convergence acceleration

C. Brezinski, M. Redivo Zaglia

• In this paper, we give some new algebraic properties of a sequence transformation due to Drummond for accelerating the convergence. In the particular case where the terms of the sequence to be transformed are the partial sums of a formal power series, this transformation leads to Padé-type approximants. Then, using various operators, some extensions of Drummond's process are proposed, and their properties are given. A new expression for the E-transformation, using generalized divided differences, is obtained, and it is also generalized. The recurrence relation for these differences can be used for its implementation, and the Ford�Sidi algorithm is also related to them. Lubkin's T and W-transformations, which could be related to Drummond's, are discussed in Appendix A.