A235336 Numbers having evil number of 1's in their binary representation.

0, 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, 131

Offset

0,2

Comments

A000120(a(n)) is in A001969.

Except for 0, the first term in which the sequence differs from A075930 is the 27th: a(27) = 63.

Also a(27) = 63 is the first odd term that is not in A092246. - Altug Alkan, Mar 18 2018

Links

Robert Israel, Table of n, a(n) for n = 0..10000

Example

7 in binary has 3 1's and since 3 is evil (i.e., belongs to A001969), then 7 is in the sequence.

Maple

filter:= n ->
  convert(convert(convert(convert(n, base, 2), `+`), base, 2), `+`)::even:
select(filter, [$0..131]); # Robert Israel, Mar 18 2018

Mathematica

Select[Range[0, 150], EvenQ[DigitCount[DigitCount[#, 2, 1], 2, 1]] &] (* Amiram Eldar, Jul 24 2023 *)

Crossrefs

Cf. A000120, A001969, A075930, A092246.

Sequence in context: A155501 A271500 A271499 * A075930 A014311 A337459

Adjacent sequences: A235333 A235334 A235335 * A235337 A235338 A235339

Keyword

nonn,base

Author

Vladimir Shevelev, Jan 06 2014

Status

approved