From paper (On first integrals of second-order ordinary differential equations by Romero
et all), this is called class B. The first integral is
\[ \frac {d}{dx}R=C\left ( x\right ) +\frac {1}{A\left ( x,y\right ) y^{\prime }+B\left ( x,y\right ) }\]
where
\(C_{y}=0\). Another class of ode’s is called
class
\(A\) with first integral
\[ \frac {d}{dx}R=\frac {1}{A\left ( x,y\right ) y^{\prime }+B\left ( x,y\right ) }\]
This is subset of class B.