DSolve[Derivative[1][y][x] == (1 - 2*x + x^4 + x^6 - y[x] + 2*x^3*y[x] + 3*x^5*y[x] + x^2*y[x]^2 + 3*x^4*y[x]^2 + x^3*y[x]^3)/x,y[x],x]