fn e1_taylor_coefficients(n: isize) -> Vec<f64> { use natural_constants::math::euler_mascheroni; if n < 0 { panic!("n ≥ 0 is required"); } if n == 0 { return vec![]; } if n == 1 { return vec![-euler_mascheroni]; } let mut term = 1.0; let mut terms = vec![-euler_mascheroni, term]; for k in 2..=n { let k = k as f64; term = -term * (k - 1.0) / (k * k); terms.push(term); } terms } fn evalpoly64_impl(i