The above is the correct answer. An intuitive way to understand this is that pay increases by a multiple of $5 each week after the first.
Week 1 pay = $1
Week 2 pay = week 1 pay × $5 = $5 or $5^1
Week 3 pay = week 2 pay × $5 = $25 or $5^2
...
Week 30 pay = week 29 pay × $5 = $5^(30-1) or $5^29