Leonardo Fibonacci discovered the Fibonacci number sequence by studying the growth of an idealized rabbit population. The problem he considered was how many pairs of rabbits would be produced in one year from a single pair, assuming that each pair of rabbits produces a new pair every month starting from their second month of life, and that rabbits never die. This scenario led to the recursive sequence where the number of rabbit pairs in the nth month equals the sum of the pairs in the previous month and the pairs two months earlier. This sequence is now known as the Fibonacci sequence
. In summary, the animal Fibonacci was studying when he discovered the sequence was rabbits.
