- A little reminder: if you find a PRP of the form
2^n-3 or 2^n+3 (for any n, not just a prime) you may
have prospects of a BLS (which failing a KP) proof
by looking at work on factorization of Phi(2,k),
since, in *either* case, *both* N-1 and N+1 are
algebraically factorizable into these intensively
studied base-2 cyclotomic numbers:
Apologies to those for whom this is blindingly obvious.