Rabbit Series

Rabbit Series

Rabbit sequence usually refers to the following sequence:
1,1,2,3,5,8,13,21,……
A pair of little rabbits grow into big rabbits in the second month, and give birth to a pair of little rabbits in the third month. Every pair of little rabbits grow into big rabbits in the second month, and give birth to a pair of little rabbits in the third month. Suppose these rabbits are not dead, and can always reproduce. Then, the number of rabbits per month constitutes the above sequence