User:Crassworm

http://www.research.att.com/~njas/sequences/A084386 Number of pairs of rabbits when there are 3 pairs per litter and offspring reach parenthood after 3 gestation periods.

http://www.research.att.com/~njas/sequences/A072465 A Fibonacci-like model in which each pair of rabbits dies after the birth of their 4-th litter: a(n) = a(n-2) + a(n-3) + a(n-4) + a(n-5).

y=1, a, f=1, i=inf: nth a-nacci number: $p(n) = \sum_{j=1}^a p(n-j)$

$p (n) = p (n - 1) + y p (n - f) - y p (n - i)$

$p (n) = 0$ when $n < 0$

$p (n) = 1$ when $n = 0$

$p (n) = p (n) - 1$ when $n = a$