Question

There is no function equation for the Fibonacci numbers, you have to use a Recursion formula.

F(n) = F(n-1) + F(n-2) for n>2 and F(1)=1, F(2)=1

what is the equation for the fibonacci sequence

Answer 1

Actually, there are a number of closed forms for Fn, but they are usually complicated. For example, Fn =

floor((n-1)/2)
∑ (n-k-1)Ck
k=0

where nCk is the combinations of n things k at a time

or

((1+√5)^n - (1-√5)^n)/(2^n √5)