  An explicit check of the AGT relation between the W_N-symmetry controlled
conformal blocks and U(N) Nekrasov functions requires knowledge of the
Shapovalov matrix and various triple correlators for W-algebra descendants. We
collect simplest expressions of this type for N=3 and for the two lowest
descendant levels, together with the detailed derivations, which can be now
computerized and used in more general studies of conformal blocks and AGT
relations at higher levels.
