\[ \int \frac {\left (a+b x^3\right )^5 \left (A+B x^3\right )}{x^{15}} \, dx \]
Optimal antiderivative \[ -\frac {a^{5} A}{14 x^{14}}-\frac {a^{4} \left (5 A b +a B \right )}{11 x^{11}}-\frac {5 a^{3} b \left (2 A b +a B \right )}{8 x^{8}}-\frac {2 a^{2} b^{2} \left (A b +a B \right )}{x^{5}}-\frac {5 a \,b^{3} \left (A b +2 a B \right )}{2 x^{2}}+b^{4} \left (A b +5 a B \right ) x +\frac {b^{5} B \,x^{4}}{4} \]
command
integrate((b*x**3+a)**5*(B*x**3+A)/x**15,x)
Sympy 1.10.1 under Python 3.10.4 output
\[ \text {Timed out} \]
Sympy 1.8 under Python 3.8.8 output
\[ \frac {B b^{5} x^{4}}{4} + x \left (A b^{5} + 5 B a b^{4}\right ) + \frac {- 44 A a^{5} + x^{12} \left (- 1540 A a b^{4} - 3080 B a^{2} b^{3}\right ) + x^{9} \left (- 1232 A a^{2} b^{3} - 1232 B a^{3} b^{2}\right ) + x^{6} \left (- 770 A a^{3} b^{2} - 385 B a^{4} b\right ) + x^{3} \left (- 280 A a^{4} b - 56 B a^{5}\right )}{616 x^{14}} \]