Respuesta :

Step-by-step explanation:

Given formula

an = n² + 4

Now the first four terms of the sequence are

a1 = 1² + 4 = 5

a2 = 2² + 4 = 4 + 4 = 8

a3 = 3² + 4 = 9 + 4 = 13

a4 = 4² + 4 = 16 + 4 = 20

The terms are

5 , 8 , 13 and 20.