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A223024
Numbers k such that 3^k is odious (A000069).
4
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
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
Complement of A371970.
Sequence in context: A309688 A072125 A370759 * A275340 A082206 A115566
KEYWORD
nonn,base
AUTHOR
Vladimir Shevelev, Mar 29 2013
STATUS
approved