A054513 Log_b 10 where b is smallest primitive root (A001918) mod n-th prime.

5, 10, 3, 17, 3, 23, 14, 24, 8, 10, 19, 48, 7, 23, 16, 34, 9, 66, 28, 86, 35, 25, 45, 48, 25, 95, 33, 47, 85, 87, 105, 32, 142, 16, 41, 40, 139, 157, 94, 35, 90, 46, 133, 47, 12, 119, 5, 204, 88, 115, 103, 191, 209, 54, 148, 110, 110, 174, 94, 218, 1, 244, 27, 1, 278, 315

Offset: 5

Author

N. J. A. Sloane, Apr 09 2000

Keywords

• nonn
• easy

References

• Tom M. Apostol, Introduction to Analytic Number Theory, Springer-Verlag, 1976, Table 10.2, pp. 216-217.

Links

• Amiram Eldar, Table of n, a(n) for n = 5..10000

Crossrefs

Cf. table in A054503.

Cf. A001918, A054505, A054506, A054507, A054508, A054509, A054510, A054511, A054512.

Programs

Mathematica

a[n_] := Module[{p, b, lg = 1}, b = PrimitiveRoot[p = Prime[n]]; While[ PowerMod[b, lg, p] != 10, lg++]; lg]; Array[a, 100, 5] (* Jean-François Alcover, Sep 03 2016 *)

PARI

a(n)=znlog(10,znprimroot(prime(n))) \\ Charles R Greathouse IV, Oct 03 2011

Extensions

More terms from James Sellers, Apr 09 2000