Look at the description for the equation. Find the subscript that will make the following equation true:

Question

2(FN+2) - FN+3 = F?

 

We are dealing with Fibonacci numbers here.
The given equations are:
2(2)-3=1
2(3)-5=1
2(5)-8=2
2(8)-13=3

Based on this info, what is the subscript "?"

Answer 1

For the Fibonacci sequence:

a₁ = 1

a₂ = 1

a_n = a_n-2 + a_n-1