A179676 Numbers m=2*n-1 for all n>2 not in A179460.

7, 15, 21, 23, 31, 35, 39, 45, 47, 49, 51, 55, 63, 71, 73, 75, 79, 85, 87, 89, 91, 93, 95, 103, 105, 111, 115, 117, 119, 123, 127, 133, 135, 143, 147, 151, 153, 155, 159, 161, 165, 167, 175, 183, 187, 189, 191, 195, 199, 215, 217, 219, 221, 223, 225, 231, 233, 235, 237, 239, 245, 247, 253, 255, 259

Offset: 1

Author

Vladimir Shevelev, Jul 24 2010

Keywords

• nonn
• uned

Comments

Consider the algorithm of calculation ord_(2n-1)(2) in A179680, and the average of the 2-adic orders l_1, ..., l_k defined there. For terms of the sequence it is more than 2, while for other odd numbers(>=3), it equals 2. This means that only for the terms of the sequence the number of odd residues in {1,2,...,2^ord_(2*n-1)(2)} (considered in the reduced residue system modulo 2*n-1)less than even ones.

Crossrefs

Cf. A179460, A007814, A002326