Question 825128
Sequence: 1, 9, 25, 49, ...

a) Find a6
b) Find an

each number is the square of each odd consecutive number (1, 3, 5, 7, ...) and a6 = 121 but there has to be algebraic work to show how a6 = 121 
my teacher's really vague about work but my guess she wants a rule that you can use to solve this sequence. I can't spot the common difference/ratio.

all i have so far is a6=5d+1 or a6=r^5

i know how to determine if this is an arithmetic or geometric sequence but this ones confusing me :(
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a6 = 121
an = (2n-1)^2