Hi All,

I was wondering if you could help me with the below...

. If the sequence x(1), x(2), x(3), …, x(n), … is such that x(1) = 3 and x(n+1) = 2x(n) – 1 for n ≥ 1, then x(20) – x(19) =

A. 2^19

B. 2^20

C. 2^21

D. (2^20) - 1

E. (2^21) - 1

I'm drawing a complete blank. x(n+1) = 2x(n) - 1 would ellude to x(20) being 2x(value of 19) -1. = 2x(19) - 1 = 38x - 1 which seems completely off? Do I have to substitute all the way from x(1) to x(19) to determine the value?

Thanks in Advance.