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

Author

N. J. A. Sloane, Apr 16 2016

Keywords

• nonn
• base

Examples

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

Links

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

Crossrefs

Complement of A143071.

Similar to but different from A075930, A235336 and A271500.

Programs

Mathematica

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

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