Question

what is the 100th term for the sequence 1,4,9,16​

Answer 1

You can observe that

$a_1=1=1^2$

$a_2=4=2^2$

$a_3=9=3^2$

$a_4=16=4^2$

So, we can extrapolate the general rule

$a_n=n^2$

So, the 100th term will be

$a_{100}=100^2=10000$