A271499 Positive numbers n such that the number of 1's in the binary expansion of n is not a power of 2.

7, 11, 13, 14, 19, 21, 22, 25, 26, 28, 31, 35, 37, 38, 41, 42, 44, 47, 49, 50, 52, 55, 56, 59, 61, 62, 63, 67, 69, 70, 73, 74, 76, 79, 81, 82, 84, 87, 88, 91, 93, 94, 95, 97, 98, 100, 103, 104, 107, 109, 110, 111, 112, 115, 117, 118, 119, 121, 122, 123, 124, 125, 126, 127, 131, 133, 134, 137, 138, 140

Offset

1,1

Links

Michel Marcus, Table of n, a(n) for n = 1..10000

Example

127 = 1111111_2 has seven 1's, so is a term (this distinguishes the sequence from A235336).

Mathematica

Select[Range@ 140, ! IntegerQ@ Log2@ First@ DigitCount[#, 2] &] (* Michael De Vlieger, Apr 16 2016 *)

Prog

(PARI) lista(nn) = {for (n=1, nn, my(nbd = hammingweight(n)); if (!((nbd==1) || (nbd==2) || (ispower(nbd, , &k) && (k==2))), print1(n, ", ")); ); } \\ Michel Marcus, Apr 16 2016
(Python)
A271499_list = [n for n in range(1, 10**6) if bin(bin(n).count('1')).count('1') != 1] # Chai Wah Wu, Apr 16 2016

Crossrefs

Complement of A143071.

Similar to but different from A075930, A235336 and A271500.

Sequence in context: A119393 A155501 A271500 * A235336 A075930 A014311

Adjacent sequences: A271496 A271497 A271498 * A271500 A271501 A271502

Keyword

nonn,base

Author

N. J. A. Sloane, Apr 16 2016

Status

approved