Which of the following numbers will replace the question mark (?) in the given series? 13, 14, 23, 48, 97, 178, ?

The differences between consecutive terms are: 1, 9, 25, 49, 81 — these are squares of odd numbers (1², 3², 5², 7², 9²). The next difference should be 11² = 121. So 178 + 121 = 299.