OFFSET
1,1
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
KEYWORD
nonn,hard
AUTHOR
Peter Luschny, Mar 17 2020
EXTENSIONS
More terms from Robert Israel, Mar 17 2020
STATUS
approved