Iterative Fibonacci algorithm

int fibmax = 20

int fibonacci(int n)
    int u = 0
    int v = 1
    int t
    for int i in 2 .. n
        t = u + v
        u = v
        v = t
    /for
return v

for int x in 1..fibmax echo "fib(" , x , ") ", fibonacci(x), "\n"