Find an explicit formula for the geometric sequence 2\,,\,6\,,\,18\,,\,54,...2,6,18,54, ...2, comma, 6, comma, 18, comma, 54, comma, point, point, point. Note: the first term should be \textit{b(1)}b(1)start text, b, left parenthesis, 1, right parenthesis, end text. b(n)=b(n)=b, left parenthesis, n, right parenthesis, equals