Hi, you did not mention where you are doing your collecting; but you are correct, the hickory leaf is pinnately compound. I found a good visual resource to help folks compare simple and compound leaves.
Here it is: https://www.treehugger.com/simple-and-compound-tree-leaf-4051112#toc-double-pinnately-compound
The website also gives examples of tree species with different types of leaves. For doubly compound, you will be looking for double pinnately compound or bipinnate. Enjoy! Lyn H