To start with a dubious assumption: any given pair of baby rabbits don't breed in their first two months. In their third month, however (and every month after that) they produce another pair.

Unsurprisingly, this situation produces a very familiar recurrence relationship: The number of baby rabbits in month n clearly equals the total number of rabbits in month n - 2.

Hence U(n) = U(n-2) + U(n-1)

...Suppose that I very misguidedly decide that my rabbitbreeding is going too slowly: in the second month I buy two more pairs of babyrabbits. How many pairs do I have as time goes on?

Month:

Number of pairs :

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Imagine that the rabbits' fertility was delayed by an extra month. What impact would that have?

Month:

Number of Pairs:

N:

Result: