\[ y''(x)-6 y(x)^2=0 \] ✓ Mathematica : cpu = 0.0659079 (sec), leaf count = 14
DSolve[-6*y[x]^2 + Derivative[2][y][x] == 0,y[x],x]
\[\{\{y(x)\to \wp (x+c_1;0,c_2)\}\}\] ✓ Maple : cpu = 0.861 (sec), leaf count = 10
dsolve(diff(diff(y(x),x),x)-6*y(x)^2=0,y(x))
\[y \left (x \right ) = \WeierstrassP \left (x +c_{1}, 0, c_{2}\right )\]