What is the difference between sixth and fifth terms of the sequence 2,4,7, __

What is the difference between sixth and fifth terms of the sequence 2,4,7, ___ whose n^th term is n + 2^n-1

A 3

B 6

C 16

D 17

Correct Answer: Option D

here,

aⁿ=n+2n−1

so, sixth term, a⁶= 6+26−1= 38

fifth terms of the sequence, a⁵= 5+25−1= 21;

The difference is 38-21= 17