Answer:
a_n = n^2 − 1
Step-by-step explanation:
The numbers can be described as a polynomial with the following formula:
a1 = 1^2 − 1 = 1 - 1 = 0
a2 = 2^2 − 1 = 4 - 1 = 3
a3 = 3^2 − 1 = 9 - 1 = 8
a4 = 4^2 − 1 = 16 - 1 = 15
a5 = 5^2 − 1 = 25 - 1 = 24
