OFFSET
1,1
COMMENTS
The sequence is probably infinite. If so, then there are infinitely many primes for which 2 is a primitive root (A001122).
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
m = 1; s = {}; While[Prime[m] < 10000, m = m + 1; p = Prime[m]; pf = FactorInteger[p - 1]; L = Length[pf]; j = 0; While[j < L, j = j + 1; q = First[pf[[j]]]; If[MultiplicativeOrder[q, p] == p - 1, , j = L + 1]; If[j == L, s = {s, p}, ] ] ]; s = Flatten[s]
CROSSREFS
KEYWORD
nonn
AUTHOR
Emmanuel Vantieghem, Jan 24 2010
STATUS
approved