Fn+p⁡(z)∼(-1)n⁢ⅈ⁢ⅇ-p⁢π⁢ⅈ⁢(12⁢erfc⁡(12⁢ρ⁢c⁡(θ))-ⅈ⁢ⅇⅈ⁢ρ⁢(π-θ)⁢ⅇ-ρ-z(2⁢π⁢ρ)1/2⁢∑s=0∞h2⁢s⁡(θ,α)ρs).