Answer:
the formula is a_n = 6n - 5
Step-by-step explanation:
The formula is
Given that
{1, 7, 13, 19, 25, . . . }
The difference between the numbers is
7 - 1 = 6
13 -7 = 6
19 - 13 = 6
a = 1
d = 6
Now the formula is
a_n = a + (n - 1)d
= 1 + (n - 1)6
= 1 + 6n - 6
= 6n - 5
So, the formula is a_n = 6n - 5