This Report (NM-R9609, March 1996) updates the tables of factorizations of $a^n pm 1$ for $13 le a < 100$, previously published as CWI Report NM-R9212 (June 1992) and updated in CWI Report NM-R9419 (September 1994). A total of 760 new entries in the tables are given here. The factorizations are now complete for $n < 67$, and there are no composite cofactors smaller than $10^{94$.

Arithmetic functions; related numbers; inversion formulas (msc 11A25), Explicit machine computation and programs (not the theory of computation or programming) (msc 11-04)
Department of Numerical Mathematics [NM]
Large-scale computing

Brent, R.P, Montgomery, P.L, & te Riele, H.J.J. (1996). Factorizations of $ a ^ n $ + 1, 13 < a < 100 : update 2. Department of Numerical Mathematics [NM]. CWI.