Asymptotic and factorial expansions of Euler series truncation errors via exponential polynomials

A detailed analysis of the remainder obtained by truncating the Euler series up to the nth-order term is presented. In particular, by using an approach recently proposed by Weniger, asymptotic expansions of the remainder, both in inverse powers and in inverse rising factorials of n, are obtained. It is found that the corresponding expanding coefficients are expressed, in closed form, in terms of exponential polynomials, well known in combinatorics, and in terms of associated Laguerre polynomials, respectively. A study of the divergence and/or of the convergence of the above expansions is also carried out for positive values of the Euler series argument. (C) 2010 IMACS. Published by Elsevier B.V. All rights reserved