Function fermat_number 

pub const fn fermat_number(n: u32) -> u128

n-th Fermat number: 2^(2^n) + 1.

Returns u128::MAX for n >= 7 (would overflow: 2^(2^7) = 2^128).

Examples

use mathverse_core::integer::fermat_number;

assert_eq!(fermat_number(0), 3);
assert_eq!(fermat_number(1), 5);