A173933 The number of numbers m < k/2 such that m/k is a reduced fraction in the Cantor set, where k= A173931(n).

1, 2, 3, 3, 4, 8, 6, 15, 6, 6, 8, 15, 8, 12, 8, 8, 10, 24, 27, 16, 12, 9, 63, 10, 16, 12, 63, 20, 12, 11, 10, 36, 12, 56, 12, 12, 44, 12, 15, 36, 12, 16, 120, 60, 110, 24, 16, 18, 24, 225

Offset: 1

Author

T. D. Noe, Mar 03 2010

Keywords

• nonn

Comments

When k is a prime of the form (3^r-1)/2, then the m are 2^r-1 numbers (greater than 0) whose base-3 representation consists of only 0's and 1's. Hence, for r=3,7, and 13, the primes k are 13, 1093, and 797161, and the number of m < k/2 is 3, 63, and 4095.

Examples

			When k=40, then 1/k, 3/k, 9/k, and 13/k have base-3 representations containing only the digits 0 and 2.
		

Links

• T. D. Noe, Table of n, a(n) for n = 1..185

Crossrefs

Cf. A005823, A005836, A007734, A076481, A173931, A173934.

Programs

Mathematica

Length /@ Last[Transpose[cantor]] (* see A173931 *)

Extensions

Name qualified by Peter Munn, Jul 14 2019