A179460 Numbers m for which 2*A179382(m)=A002326(m-1).

2, 3, 5, 6, 7, 9, 10, 13, 14, 15, 17, 19, 21, 22, 27, 29, 30, 31, 33, 34, 35, 39, 41, 42, 49, 50, 51, 54, 55, 57, 61, 63, 65, 66, 69, 70, 71, 73, 75, 79, 82, 85, 86, 87, 89, 90, 91, 93, 97, 99, 101, 102, 103, 104, 105, 106, 107, 114, 115, 121, 122, 125, 126, 129, 133, 135

Offset: 1

Author

Vladimir Shevelev, Jul 14 2010

Keywords

• nonn

Comments

m is in the sequence iff the set {1,2,...,2^(2*m-2)} considered in reduced residue system modulo 2*m-1 contains the same number of odd and even integers.

Examples

			5 in the sequence since modulo 2*5-1=9 we have {1,2,4,8,16,32}={1,2,4,8,7,5} and the last set contains 3 odd and 3 even elements.
		

Crossrefs

Cf. A002326, A179382.

Programs

Mathematica

fQ[n_] := Block[{r = Union@ PowerMod[2, Range[0, 2 n - 2], 2 n - 1]}, Length@ r == 2 Count[ OddQ@ r, True]]; Select[ Range@ 138, fQ] (* Robert G. Wilson v, Aug 26 2010 *)

Extensions

More terms from Robert G. Wilson v, Aug 26 2010