A298879 Numbers whose square is not odious.

0, 3, 6, 12, 13, 15, 21, 24, 26, 27, 30, 37, 42, 45, 47, 48, 52, 53, 54, 57, 60, 61, 63, 69, 73, 74, 81, 83, 84, 90, 93, 94, 96, 99, 104, 105, 106, 107, 108, 109, 111, 114, 115, 119, 120, 122, 123, 126, 133, 137, 138, 141, 146, 148, 151, 155, 159

Offset: 1

Author

Vincenzo Librandi, Jan 31 2018

Keywords

• nonn
• easy

Comments

Complement of A235331.

From Robert Israel, Feb 02 2018: (Start)

2*n is in the sequence if and only if n is in the sequence.

2*n+1 is in the sequence if and only if n*(n+1) is odious. (End)

Crossrefs

Cf. A235001, A235331.

Programs

Magma

[n: n in [0..200] | IsEven(&+Intseq(n^2, 2))];

Maple

select(t -> convert(convert(t^2,base,2),`+`)::even, [$0..200]); # Robert Israel, Feb 02 2018

Mathematica

Join[{0}, Select[Range[200], !OddQ[DigitCount[#^2, 2][[1]]] &]]

PARI

isok(n) = (hammingweight(n^2) % 2) != 1; \\ Michel Marcus, Jan 31 2018