The pattern is given below
1, 3, 9, 27
We can clearly see that the terms are indeed the powers of 3
i.e
[tex]\begin{gathered} 3^0\text{ = 1} \\ 3^1\text{ = 3} \\ 3^2\text{ = 9} \\ 3^3\text{ =27} \end{gathered}[/tex]looking closely at the sequence generated, we can show that it follows the geometric sequence as
[tex]r\text{ = }\frac{T_2}{T_1}\text{ = }\frac{T_3}{T_2}\text{ = }\frac{T_{n+1}}{T_n}[/tex]Thus, the common ratio r equals
[tex]r\text{ = }\frac{3}{1}\text{ = }\frac{9}{3}\text{ = }\frac{27}{9}\text{ = 3}[/tex]for any two consecutive numbers in the sequence
Hence, we can express the sequence as a numeric sequence thus:
[tex]\begin{gathered} \text{Recall that T}_n=ar^{n-1} \\ T_n=(1)(3)^{n-1} \\ T_n=3^{n-1} \end{gathered}[/tex]We can also create a table of values to show that this sequence follows the geometric sequence