fn c(j1: i32, j2: i32, j3: i32, m3: i32) -> f64Expand description
The coefficient A(j3) of the three-term recurrence of Schulten and Gordon (1975)
in j3, j3 A(j3 + 1) f(j3 + 1) + B(j3) f(j3) + (j3 + 1) A(j3) f(j3 - 1) = 0 for
f(j3) = (j1 j2 j3; m1 m2 m3): Eq. (7) of Y.-L. Xu, J. Comput. Phys. 139, 137
(1998), as cited by treams (_coeffc).