Answer:
Domain: [tex]n\ge1[/tex]
Step-by-step explanation:
For a geometric sequence, the n-th term is given by:
[tex]a_n=a_1r^{n-1}[/tex]
From the question, [tex]a_1=1[/tex] and [tex]r=6[/tex].
Hence the explicit formula for the sequence is:
[tex]a_n=6^{n-1}[/tex], where [tex]n\ge1[/tex]
Therefore the domain is natural numbers or positive integers.