Fibonacci was an Italian mathematician. The Fibonacci numbers are so called because they were made popular by Fibonacci in 1202 A.D in his book Liber Abaci when he posed a puzzle and its solution [n]. The puzzle is about counting the number of pairs of rabbits as rabbit population grows:
Make the following assumptions: rabbits never die, a female rabbit always produces a pair of male and female offsprings and it takes one month for a female rabbit to produce a pair of offsprings. We start with 1 pair of rabbits.
- Suppose a pair of rabbits mate in month 1. Observe that there is 1 pair of rabbits at the end of the 1st month.
- The female rabbit produces a pair of offspring in month 2. Observe that there are now 2 pairs of rabbits at the end of month
- The female rabbit from the original pair produces a new pair of offsprings in month 3. Observe that there are now 3 pairs of rabbits at the end of month
- The female rabbit from the original pair produces a new pair of offsprings in month 5. Also, the female rabbit from the pair of offspring produced at the end of month 2 produces a pair of offsprings as well. There are now 5 pairs of rabbits at the end of month 3.
This process continues and the number of pairs of rabbits at the end of each month is: 1, 1, 2, 3, 5, 8, 13, …. The reader may notice that this is the Fibonacci sequence discussed at the beginning of this paper.