Mathematics problem of the first day of junior high school: look at the law of 0, 3, 8, 15, 24, 35, ---- this group of numbers, what is the 100th? What is the nth?

Mathematics problem of the first day of junior high school: look at the law of 0, 3, 8, 15, 24, 35, ---- this group of numbers, what is the 100th? What is the nth?

The rule is that the nth number is n & sup2; - 1
100 is 100 & sup2; - 1 = 9999
N is n & sup2; - 1