Let a be the first term and d be the common difference.

Given: a₇ = - 1

a₁₆ = 17

Now, Consider a₇ = - 1

⇒ a + 6d = - 1 …………(1)

Consider a₁₆ = 17

⇒ a + 15d = 17 …………(2)

Subtract equation (1) from (2), we get,

9d = 18

⇒ d = 2

∴ Common difference = d = 2

Now, from equation (1), we get,

a = - 1 - 6d

= - 1 - 6(2)

= - 13

Now, n^th term of the AP is given by

a_n = a + (n - 1)d

= - 13 + (n - 1)2

= 13 + 2n - 2

= 2n - 15