Question

Find the first six terms of the sequence.

a1 = 1, an = 4 • an-1

A) 0, 4, 4, 8, 12, 16
B) 4, 16, 64, 256, 1024, 4096
C) 1, 4, 8, 12, 16, 20
D) 1, 4, 16, 64, 256, 1024

Answer 1

D

Explanation:

Using the recursive formula with a₁ = 1

a₂ = 4 × a₁ = 4 × 1 = 4

a₃ = 4 × a₂ = 4 × 4 = 16

a₄ = 4 × a₃ = 4 × 16 = 64

a₅ = 4 × a₄ = 4 × 64 = 256

a₆ = 4 × a₅ = 4 × 256 = 1024

The first 6 terms are

1, 4, 16, 64, 256, 1024 → D