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# Explicit formulas for geometric sequences

## Problem

Wang Lei and Amira were asked to find an explicit formula for the sequence 30, comma, 150, comma, 750, comma, 3750, comma, point, point, point, where the first term should be g, left parenthesis, 1, right parenthesis.
Wang Lei said the formula is g, left parenthesis, n, right parenthesis, equals, 30, dot, 5, start superscript, n, minus, 1, end superscript, and
Amira said the formula is g, left parenthesis, n, right parenthesis, equals, 6, dot, 5, start superscript, n, end superscript.
Which one of them is right?