How does this sequence arise? It was first introduced in 1202 by Leonardo of Pisa, better known as Fibonacci, in the form of his celebrated Rabbit Problem. A female rabbit is born and after two months reaches maturity and thereafter gives birth to a daughter each month. The number of female rabbits we have at the beginning of each month is then given by the Fibonacci numbers,for there is 1 rabbit at the beginning of the first month, and the second, but at the start of the third month she gives birth to a daughter so we then have 2 rabbits. Next month she has another,giving 3 and the month after that we have 5 bunnies as both mother and her eldest daughter are now old enough to breed. In general, at the beginning of each month thereafter, the number of newborn daughters equals the number of females we had two months ago, as only they are old enough to breed. It follows that the number of females we have at the start of each subsequent month equals the total of the previous month(Fibonacciís rabbits are immortal)plus the number we had the month before that.Therefore the rule of formation of the Fibonacci numbers exactly matches the breeding pattern of his rabbits.