A099248 Numbers such that length in binary representation and number of ones have a common divisor greater than 1.

3, 7, 9, 10, 12, 15, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 56, 57, 58, 60, 63, 127, 129, 130, 132, 135, 136, 139, 141, 142, 144, 147, 149, 150, 153, 154, 156, 159, 160, 163, 165, 166, 169, 170, 172, 175, 177, 178, 180

Offset: 1

Author

Reinhard Zumkeller, Oct 08 2004

Keywords

• nonn
• base

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 (first 1810 terms from Diana Mecum)
• Index entries for sequences related to binary expansion of n.

Crossrefs

Complement of A099247.

Cf. A000120, A007088, A070939, A099244.

Programs

Haskell

a099248 n = a099248_list !! (n-1)
a099248_list = filter ((> 1) . a099244) [1..]
-- Reinhard Zumkeller, Oct 10 2013

Mathematica

Select[Range[200], !CoprimeQ[BitLength[#], DigitCount[#, 2, 1]] &] (* Amiram Eldar, Jul 16 2023 *)

Formula

A099244(a(n)) > 1.

Extensions

Corrected by Leroy Quet, Sep 04 2008

a(34) and beyond from Diana L. Mecum, Jan 04 2009