Re: Bug in SeriesCoefficient in 7.0

*To*: mathgroup at smc.vnet.net*Subject*: [mg98050] Re: Bug in SeriesCoefficient in 7.0*From*: ADL <alberto.dilullo at tiscali.it>*Date*: Sun, 29 Mar 2009 02:42:46 -0500 (EST)*References*: <gqia68$okh$1@smc.vnet.net>

Given that the bug is there, a possible workaround in version 7 could be to use FindSequenceFunction: NC = 9; (* numeber of coefficients required *) gf = FindSequenceFunction[ Table[ {n, SeriesCoefficient[Exp[-2*z]/(1 - z)^2, {z, 0, n}]}, {n, 0, NC} ], n]; sgf = FullSimplify[gf, n \[Element] Integers] ====> (E^2*(-1)^n*2^(n + 2) + Gamma[n + 4, -2]) / (E^2*Gamma[n + 3]) If we call gf6 the coefficient form returned by Mathematica 6.01, FullSimplify[gf6 - sgf] returns 0. ADL