By now the pattern should be clear: the number of competitive pairs is
7 + 6 + 5 + 4 + 3 + 2 + 1 = 28
In general, for a population of N animals, the number of competitive pairs is
1 + 2 + ... + (N-1),
and this sum is known to
equal
Pn+1 = (1 + B - D)*Pn - C*(Pn - 1)*Pn/2.
Return to the Logistic Map.