def fibonacci(n):
    """ Returns n elements of the fibonacci series"""
    fibo = [1, 1]
    if n < 1 or n > 2_000_000:
        return []
    elif n < 2:
        return fibo[:n]

    for i in range(2, n):
        fibo.append(sum(fibo[i - 2 : i]))

    return fibo