Assumptions:
TeX:
F_{n} = \frac{1}{{2}^{n - 1}} \sum_{k=0}^{\left\lfloor \left( n - 1 \right) / 2 \right\rfloor} {5}^{k} {n \choose 2 k + 1}
n \in \mathbb{Z}_{\ge 0}Definitions:
| Fungrim symbol | Notation | Short description |
|---|---|---|
| Fibonacci | Fibonacci number | |
| Pow | Power | |
| Sum | Sum | |
| Binomial | Binomial coefficient | |
| ZZGreaterEqual | Integers greater than or equal to n |
Source code for this entry:
Entry(ID("b8ed8f"),
Formula(Equal(Fibonacci(n), Mul(Div(1, Pow(2, Sub(n, 1))), Sum(Mul(Pow(5, k), Binomial(n, Add(Mul(2, k), 1))), For(k, 0, Floor(Div(Sub(n, 1), 2))))))),
Variables(n),
Assumptions(Element(n, ZZGreaterEqual(0))))