[tex]\huge\boxed{161}[/tex]
Let's start by finding the first 15 perfect square numbers ([tex]1^2, 2^2, 3^2, ...[/tex]):
[tex]1,4,9,16,25,36,49,\bold{64},81,100,121,144,169,196,\bold{225}[/tex]
Next, we just need to find the difference between the 15th perfect square number and the 8th perfect square number, which I've made bold in the list above.
[tex]225-64\\\boxed{161}[/tex]
