✓ Mathematica : cpu = 0.524225 (sec), leaf count = 47
DSolve[y[x]^2 - (a + 2*x*y[x])*Derivative[1][y][x] + x^2*Derivative[1][y][x]^2 == 0,y[x],x]
✓ Maple : cpu = 0.046 (sec), leaf count = 36
dsolve(x^2*diff(y(x),x)^2-(2*x*y(x)+a)*diff(y(x),x)+y(x)^2 = 0,y(x))