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$Aut(F_2)$ is generated by torsion, and $Aut(F_n)$ is normally generated by $Aut(F_2)$$Aut(F_n)$ is normally generated by $Aut(F_2)$, so $Aut(F_n)$ is generated by torsion, hence $Out(F_n)$.
$Aut(F_2)$ is generated by torsion, and $Aut(F_n)$ is normally generated by $Aut(F_2)$, so $Aut(F_n)$ is generated by torsion, hence $Out(F_n)$.
