So the sequence, early on, is 1, 2, 3, 5, 8, 13, 21 and so on. NUMBERS AND PLANTS To see how it works in nature, go outside and find an intact pine cone (or any other cone).

Though the Fibonacci sequence shows up everywhere in nature, these young mathematicians were surprised to find it in the answer to a variation of the pick-up sticks problem⁠—a nearly two-century-old f ...

One set rises gradually, another moderately and the third steeply. Count the number of spirals and you’ll find eight gradual, 13 moderate and 21 steeply rising ones. Fibonacci numbers again.