GeneralizedFibonacc​i.m

GeneralizedFibonacci(n,a,b) returns the generalized Fibonacci number.

For fixed integers a and b with D = a^2 + 4*b positive, the sequence U_n = GeneralizedFibonacci(n,a,b) satisfies the recurrence U_n = a U_{n-1} + b U_{n-2} with initial conditions U_0 = 0 and U_1 = 1. If a=b=1, this is the Fibonacci sequence.