If a1=2 and an=2an-1 find the first 5 sequences

The first 5 terms of the sequence are 2, 4, 8, 16 and 32.

Step-by-step explanation:

Given:

= 2

= 2   -----------------(i)

To get the first 5 terms of the sequence, substitute in turn, n = 1, 2, 3, 4, 5 into equation (i).

The first term (when n = 1) has been given as:

= 2

The second term (when n = 2) is given as:

= 2

= 2    (but = 2 )

=> = 2(2)

=> = 4

The third term (when n = 3) is given as:

= 2

= 2    (but = 4 )

=> = 2(4)

=> = 8

The fourth term (when n = 4) is given as:

= 2

= 2   (but = 8 )

=> = 2(8)

=> = 16

The fifth term (when n = 5) is given as:

= 2

= 2   (but = 16 )

=> = 2(16)

=> = 32

Therefore, the first 5 terms of the sequence are 2, 4, 8, 16 and 32.