  We examine three point functions with two scalar operators and a higher spin
current in 2d W_N minimal model to the next non-trivial order in 1/N expansion.
The minimal model was proposed to be dual to a 3d higher spin gauge theory, and
1/N corrections should be interpreted as quantum effects in the dual gravity
theory. We develop a simple and systematic method to obtain three point
functions by decomposing four point functions of scalar operators with Virasoro
conformal blocks. Applying the method, we reproduce known results at the
leading order in 1/N and obtain new ones at the next leading order. As
confirmation, we check that our results satisfy relations among three point
functions conjectured before.
