  We propose a method to factor numbers based on two interacting bosonic atoms
in a central potential where the single-particle spectrum depends
logarithmically on the radial quantum numbers of the zero angular momentum
states. The bosons initially prepared in the ground state are excited by a
sinusoidally time-dependent interaction into a state characterized by the
quantum numbers which represent the factors of a number encoded in the
frequency of the perturbation. We also discuss the full single-particle
spectrum and limitations of our method caused by decoherence.
