\[ (2 x+1)^2 y''(x)-2 (2 x+1) y'(x)-12 y(x)-3 x-1=0 \] ✓ Mathematica : cpu = 0.0320147 (sec), leaf count = 47
\[\left \{\left \{y(x)\to \frac {-72 x^2-56 x-7}{192 (2 x+1)}+c_1 (2 x+1)^3+\frac {c_2}{2 x+1}\right \}\right \}\] ✓ Maple : cpu = 0.019 (sec), leaf count = 41
\[\left \{y \left (x \right ) = \frac {c_{1}}{2 x +1}+c_{2} \left (2 x +1\right )^{3}+\frac {-72 x^{2}-56 x -7}{384 x +192}\right \}\]