A172280 Primes p with the property that no divisor of p-1 is a primitive root modulo p.

17, 41, 73, 89, 97, 113, 137, 193, 233, 241, 251, 257, 281, 307, 313, 337, 353, 401, 409, 433, 439, 449, 457, 499, 521, 569, 577, 593, 601, 617, 641, 643, 673, 727, 761, 769, 809, 857, 881, 919, 929, 937, 953, 977, 997, 1009, 1013, 1033, 1049, 1097, 1129, 1153

Offset

1,1

Comments

The sequence is probably infinite.

No element of A001122 nor of A172058 can be in this list.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

m = 2; t = {}; While[m < bound, m = m + 1; p = Prime[m]; dp = Divisors[p - 1]; L = Length[dp]; j = 1; While[j < L - 1, j = j + 1; b = MultiplicativeOrder[dp[[j]], p]; If[b == p - 1, j = L + 1, ] ]; If[j == L + 1, , t = {t, p}] ]; t = Flatten[t]

Crossrefs

Cf. A001122 , A172058.

Sequence in context: A332227 A263011 A263012 * A004625 A141174 A007519

Adjacent sequences: A172277 A172278 A172279 * A172281 A172282 A172283

Keyword

easy,nonn

Author

Emmanuel Vantieghem, Jan 30 2010

Status

approved