Which number will replace the question mark (?) in the following number series? 9, 12, 17, 26, 43, 76, ?, 270

The differences between consecutive terms follow a doubling pattern: +3, +5, +9, +17, +33, +65, +129. Adding 65 to 76 gives 141, and adding 129 to 141 gives 270. So the missing term is 141.