A223024 Numbers k such that 3^k is odious (A000069).

0, 4, 7, 10, 11, 13, 15, 16, 19, 20, 22, 28, 29, 30, 34, 36, 41, 43, 46, 48, 49, 50, 53, 54, 56, 62, 63, 65, 66, 67, 68, 69, 80, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 97, 98, 100, 101, 103, 107, 108, 110, 111, 113, 114, 115, 117, 118, 119, 120

Offset

1,2

Links

Peter J. C. Moses, Table of n, a(n) for n = 1..10000

Maple

select(t -> convert(convert(3^t, base, 2), `+`)::odd, [$0..200]); # Robert Israel, Oct 10 2016

Mathematica

Select[Range[0, 200], OddQ[DigitCount[3^#, 2][[1]]]&] (* Peter J. C. Moses, Mar 30 2013 *)

Prog

(PARI) isok(n) = (hammingweight(3^n) % 2) == 1; \\ Michel Marcus, Oct 11 2016

Crossrefs

Cf. A000069, A001969, A000244, A237545.

Complement of A371970.

Sequence in context: A309688 A072125 A370759 * A275340 A082206 A115566

Adjacent sequences: A223021 A223022 A223023 * A223025 A223026 A223027

Keyword

nonn,base,changed

Author

Vladimir Shevelev, Mar 29 2013

Status

approved