What number comes next in the series: 9, 21, 45, 93, 189, ?

💡 Solution & Explanation

Each term is the previous term × 2 + 3: 9 × 2 + 3 = 21, 21 × 2 + 3 = 45, 45 × 2 + 3 = 93, 93 × 2 + 3 = 189. So the next term is 189 × 2 + 3 = 381.