A197225 Primes p with the period of the decimal fraction 1/p a prime power, A000961.

3, 11, 17, 37, 41, 53, 73, 79, 83, 101, 107, 137, 163, 173, 227, 239, 257, 271, 317, 347, 353, 359, 449, 467, 479, 563, 587, 641, 643, 719, 733, 751, 757, 773, 797, 839, 907, 1031, 1187, 1231, 1283, 1307, 1319, 1409, 1439, 1493, 1523, 1627, 1637, 1879, 1907

Offset

1,1

Links

T. D. Noe, Table of n, a(n) for n = 1..1000

Mathematica

myPerfectPowerQ[n_] := Length[FactorInteger[n]] == 1; Select[Prime[Range[500]], Mod[10, #] > 0 && myPerfectPowerQ[Length[RealDigits[1/#, 10][[1, 1]]]] &]

Crossrefs

Cf. A072859 (period is prime).

Cf. A072982 (period is a power of 2).

Cf. A128948 (period is perfect power).

Cf. A197226 (the periods of this sequence).

Cf. A129727 (period is a semiprime).

Sequence in context: A186424 A018520 A154933 * A181507 A154934 A302872

Adjacent sequences: A197222 A197223 A197224 * A197226 A197227 A197228

Keyword

nonn,base

Author

T. D. Noe, Oct 22 2011

Status

approved