Fibonacci Variation: A single pair of rabbits (male and female) is born at the beginning of a year. Asume the following conditions (which are more realistic than Fibonacci's): 1) Rabbit pairs are not fertile during their first month of life but thereafter give birth to four new male/female pairs at the end of every month,
2) No rabbits die
a) Let rn=the number of pairs of rabbits alive at the end of month n, for each integer n>=1, and let r0=1. Find the recurrence relation for r0,r1,
b) how many rabbits will there be at the end of the year.