✓ Mathematica : cpu = 1.01912 (sec), leaf count = 31
DSolve[Derivative[2][y][x] == -(y[x]/(1 + x^2)^2) - (2*x*Derivative[1][y][x])/(1 + x^2),y[x],x]
✓ Maple : cpu = 0.016 (sec), leaf count = 17
dsolve(diff(diff(y(x),x),x) = -2/(x^2+1)*x*diff(y(x),x)-1/(x^2+1)^2*y(x),y(x))