Yes! Very sensible of you! It is much simpler to represent butane like this.
Scientists thought just like you did! So, whenever the same atom repeats in a molecule, we use a number below the atom to denote how many of those atoms are in the molecule. (There are some exceptions, we can ignore them for now.)
The sugar we use for sweetening our food (chemical name Sucrose) has 12 atoms of Carbon, 22 atoms of Hydrogen and 11 atoms of Oxygen. What is its chemical formula?