I agree with Mandolin... looks like a ash tree sapling to me.
My mom has a big old ash tree in her front yard and it seeds lots of little saplings like that.
They grow real fast.
It does somewhat resemble a hickory sapling, but looks more like ash to me.
Here below is a pic of my boy with a couple little 3 prong ginseng plants.
Notice the leaf pattern, 3 larger leaves that all point out away from the center, and then 2 smaller leaves that point in towards the center. That is the pattern that catches your eye once you get your eye trained to find it.
Good Luck - keep trying.
TNhunter