In the following number series one number is wrong. Find that wrong number. 9 17 66 385 3073 30721

Series: 9, 17, 66, 385, 3073, 30721. Pattern: ×2 - 1 = 17, ×4 - 2 = 66 (should be 66), ×6 - 3 = 393 (but we have 385), ×8 - 4 = 3072 (but we have 3073), ×10 - 5 = 30715 (but we have 30721). Actually pattern is: ×2 - 1, ×4 - 2, ×6 - 3, ×8 - 4, ×10 - 5. Let's verify: 9×2-1=17✓, 17×4-2=66✓, 66×6-3=393✗(we have 385), 385 is wrong. But wait, let me check if 385 fits another pattern... Actually 66×6=396, 396-11=385. Or maybe the pattern changes. If 66 is wrong, what should replace it? If we continue from 17: 17×4=68-2=66 (correct). 66×6=396-3=393. So 385 breaks the pattern. 66 is correct.