  The Pade approximant technique and the variational Monte Carlo method are
applied to determine the ground-state energy of a finite number of charged
bosons in two dimensions confined by a parabolic trap. The particles interact
repulsively through a Coulombic, 1/r, potential. Analytic expressions for the
ground-state energy are obtained. The convergence of the Pade sequence and
comparison with the Monte Carlo results show that the error of the Pade
estimate is less than 4% at any boson density and is exact in the extreme
situations of very dilute and high density.
