What number comes next in the series: 3, 8, 18, 38, 78, ?

💡 Solution & Explanation

Each term is the previous term × 2 + 2: 3 × 2 + 2 = 8, 8 × 2 + 2 = 18, 18 × 2 + 2 = 38, 38 × 2 + 2 = 78. So the next term is 78 × 2 + 2 = 158.