Below is a diagram if a single artificial neuron $($unit$)$:

Figure $1$: Single unit with three inputs.

The node has three inputs $x=(x_1,x_2,x_3)$ that receive only binary signals $($either $0$ or $1).$ How many

different input patterns this node can receive? What if the node had four inputs? Five? Can you give a

formula that computes the number of binary input patterns for a given number of inputs?