A074204 Numbers k such that the number of 1's in the binary representation of k divides 2^k+1.

1, 2, 4, 7, 8, 11, 13, 16, 19, 21, 25, 32, 35, 37, 41, 49, 62, 64, 67, 69, 73, 81, 94, 97, 110, 118, 122, 128, 131, 133, 137, 145, 158, 161, 174, 182, 186, 193, 206, 214, 218, 230, 234, 242, 256, 259, 261, 265, 273, 286, 289, 302, 310, 314, 321, 334, 342, 346

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

Select[Range[350], Divisible[2^#+1, DigitCount[#, 2, 1]]&]  (* Harvey P. Dale, Feb 19 2011 *)

Prog

(PARI) isok(n) = !((2^n+1) % hammingweight(n)); \\ Michel Marcus, Nov 29 2013

Crossrefs

Cf. A000051, A000120.

Sequence in context: A261619 A187575 A316326 * A030355 A288307 A286060

Adjacent sequences: A074201 A074202 A074203 * A074205 A074206 A074207

Keyword

base,easy,nonn

Author

Benoit Cloitre, Sep 17 2002

Status

approved