Function fibonacci 

pub fn fibonacci(n: u64) -> u128

n-th Fibonacci number (F_0 = 0, F_1 = 1) as u128 (exact up to n = 184).

Examples

use mathverse_core::integer::fibonacci;

assert_eq!(fibonacci(0), 0);
assert_eq!(fibonacci(1), 1);
assert_eq!(fibonacci(10), 55);