Function continued_fraction 

pub fn continued_fraction(b0: f64, a: &[f64], b: &[f64]) -> f64

Evaluate a generalised continued fraction using the Lentz algorithm.

Given sequences a[i] (numerators, i ≥ 1) and b[i] (denominators, i ≥ 0), computes: b₀ + a₁/(b₁ + a₂/(b₂ + …))

Arguments

• b0 - Leading term.
• a - Numerator terms a[1], a[2], …
• b - Denominator terms b[1], b[2], …