First, interesting you are asking and I take that as a serious sign for being an airmen!
If you are current and actual and had a lot of GA hours, it may take you as low as about 2 hours and 5 landings of flight familiarization. I'll come back to you quickly. Just remember to throttle farther down on landings as you are used to - and most important, remember to let stay power longer once back in the 145 ;-).