Time evolution of the power-law index (solid black line), maximum planetesimal mass (dashed red line), and minimum planetesimal mass (dotted blue line) for the ﹩\tau =0.006﹩ (left), ﹩\tau =0.3﹩ (middle), and ﹩\tau =2﹩ (right) simulations for a period of time after planetesimals have formed. Both the power-law index, p, and the minimum planetesimal mass are relatively constant in time, whereas the maximum planetesimal mass grows slowly, presumably due to continued accretion of small particles and/or mergers with smaller planetesimals.