Q−12μ(z)+2∑n=1∞Qn−12μ(z)cos(nν)
=
eiμπ(π2)1/2Γ(μ+12)[(z2−1)μ/2(z−cosν)μ+12]
A. Erdélyi (1953): Volume I, §3.10, p. 166, eq. (3)
Reμ>−12