\[ \int \left (a^{k x}+a^{l x}\right )^4 \, dx \]
Optimal antiderivative \[ \frac {a^{4 k x}}{4 k \ln \left (a \right )}+\frac {a^{4 l x}}{4 l \ln \left (a \right )}+\frac {3 a^{2 \left (k +l \right ) x}}{\left (k +l \right ) \ln \left (a \right )}+\frac {4 a^{\left (3 k +l \right ) x}}{\left (3 k +l \right ) \ln \left (a \right )}+\frac {4 a^{\left (k +3 l \right ) x}}{\left (k +3 l \right ) \ln \left (a \right )} \]
command
integrate((a**(k*x)+a**(l*x))**4,x)
Sympy 1.10.1 under Python 3.10.4 output
\[ \text {output too large to display} \]
Sympy 1.8 under Python 3.8.8 output \[ \text {Timed out} \]_____________________________________________________