1,3,9,27,81

81 27 3 2

You can get the term to the right by multiplying the term on the left by 3.

1x3=9

3x3=9

9x3=27

27x3 = 81

multiply next term 81 by 3. So, 3 times every term after that.

The numbers are all powers of 3

3⁰, 3¹, 3², 3³, 3⁴ and 3⁵ = 243 and so on ...

Find the seventh term of this geometric sequence: 

1, 3, 9, 27,....