Indeterminate Jacobi operators

We consider the Jacobi operator (T, D(T)) associated with an indeterminate Hamburger moment problem. For a complex number z let p_z, q_z denote the square summable sequences (p_n(z)) and (q_n(z)) corresponding to the orthonormal polynomials p_n and polynomials q_n of the second kind. We determine whether linear combinations of p_u, p_v, q_u, q_v for complex u, v belong to D(T) or to the domain of the self-adjoint extensions of T in `². The results depend on the four Nevanlinna functions of two variables associated with the moment problem.