Hello, Bhavani!

Let be the number of subsets of

1) What are the values of: ?

For , we have: .

There aretwosubsets: .

. .

For , we have: .

There arefoursubsets: .

. .

For , we have: .

There areeightsubsets: .

. .

2) Set up a recurrence for and solve it.

The recurrence is: .

The closed form is: .