\[ y''(x)-6 y(x)^2-x=0 \] ✗ Mathematica : cpu = 0.163844 (sec), leaf count = 0 , could not solve
DSolve[-x - 6*y[x]^2 + Derivative[2][y][x] == 0, y[x], x]
✗ Maple : cpu = 0. (sec), leaf count = 0 , could not solve
dsolve(diff(diff(y(x),x),x)-6*y(x)^2-x=0,y(x))