Its already more than 24 hours and so new entries would not be counted and any entry before this post if correct wins or else OP wins

Consider the difference in sucessive numbers. 3-1 = 2 = 2^2 -2 = (1st prime no )^2 - (1st prime no ) 9-3 = 6 = 3^2 -3 = (2nd prime no )^2 - (2nd prime no ) 29-9 = 20 = 5^2 -5 = (3rd prime no )^2 - (3rd prime no ) 71-29 = 42 = 7^2 -7 = (4th prime no )^2 - (4th prime no ) So the answer is 71 + 11^2 - 11 = 181