A333349 a(n) is the least prime p such that n <= ord(n, p)^n < p, where ord(n, p) is the multiplicative order of n modulo p, or 1, if there is no such p.

2, 31, 757, 65537, 19531, 3154757, 2767631689, 9857737155463, 926510094425921, 440334654777631, 50544702849929377, 3335672988472972523, 846041103974872866961, 459715689149916492091, 92978587355640205970336221, 78919881726271091143763623681, 26552618219228090162977481, 1338029376807245057016053427001, 11951068054199383402102234839038071

Offset

1,1

Links

Table of n, a(n) for n=1..19.

Maple

f:= proc(n) local k, pmin, p;
  pmin:= infinity;
  for k from n while k^n < pmin do
    for p in numtheory:-factorset(n^k-1) do
      if p < pmin and p > k^n then pmin:= p fi
    od
  od;
  pmin
end proc:
f(1):= 2:
seq(f(n), n=1..18); # Robert Israel, Mar 17 2020

Crossrefs

Inspired by A333245.

Sequence in context: A245051 A024235 A010789 * A349071 A224863 A263075

Adjacent sequences: A333346 A333347 A333348 * A333350 A333351 A333352

Keyword

nonn,hard

Author

Peter Luschny, Mar 17 2020

Extensions

More terms from Robert Israel, Mar 17 2020

Status

approved