Homology of holomorphs of free groups

The holomorph of a free group Fn is the semidirect product Fn Aut(Fn). Using the methods of Hatcher and Vogtmann in [J. London Math. Soc. (2) 58 (1998) 633–635 and Math. Res. Lett. 5 (1998) 759–780], we derive stability results and calculate the mod-p homology of these holomorphs for odd primes p in dimensions 1 and 2, and their rational homology in dimensions 1 through 5. Calculations of the twisted (where Aut(Fn) acts by first projecting to and then including in ) homology follow in corresponding dimensions.