Write the next term of the following number series: 15, 29, 56, 108, 208, 400,…

Key pattern: each term equals twice the previous term minus successive powers of two (1, 2, 4, 8, 16).

• 29 = 2 × 15 − 1

• 56 = 2 × 29 − 2

• 108 = 2 × 56 − 4

• 208 = 2 × 108 − 8

• 400 = 2 × 208 − 16

• Next = 2 × 400 − 32 = 768

Answer: 768