Start with 2 baby rabbits, 1 male and 1 female. These baby rabbits became adult rabbits the next month. The month after that they produce a pair (one male, one female) of baby rabbits. Now in each subsequent month, each pair of baby rabbits reaches adulthood and each pair of adult rabbits produces a new pair(one male, one female) of baby rabbits.
Hence, the Fibonacci sequence 1, 1, 2, 3, 5, 8, 13, 21,...
Question: How many pairs of rabbits will there be after n months?
Explain why the answer is F(subn).
Any help would be much appreciated.