  We calculate energy levels of two and three bosons trapped in a harmonic
oscillator potential with oscillator length $a_{\mathrm osc}$. The atoms are
assumed to interact through a short-range potential with a scattering length
$a$, and the short-distance behavior of the three-body wave function is
characterized by a parameter $\theta$. For large positive $a/a_{\mathrm osc}$,
the energies of states which, in the absence of the trap, correspond to three
free atoms approach values independent of $a$ and $\theta$. For other states
the $\theta$ dependence of the energy is strong, but the energy is independent
of $a$ for $|a/a_{\mathrm osc}|\gg1$.
