A295889 a(n) = 1 if binary weights of n and 3n have the same parity, 0 otherwise.

1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1

Offset

0

Links

Antti Karttunen, Table of n, a(n) for n = 0..16383

Index entries for sequences related to binary expansion of n.

Index entries for characteristic functions.

Formula

a(n) = A000035(1 + A000120(n) + A000120(3*n)).

a(n) = 1 - A295890(n).

a(A003714(n)) = A095111(n).

Mathematica

a[n_] := If[Mod[DigitCount[n, 2, 1], 2] == Mod[DigitCount[3*n, 2, 1], 2], 1, 0]; Array[a, 100, 0] (* Amiram Eldar, Feb 07 2023 *)

Prog

(Scheme) (define (A295889 n) (A000035 (+ 1 (A000120 n) (A000120 (* 3 n)))))

Crossrefs

Cf. A000035, A000120, A010060, A295890.

Cf. also A003714, A095111.

Sequence in context: A188578 A322217 A104105 * A347523 A143221 A325899

Adjacent sequences: A295886 A295887 A295888 * A295890 A295891 A295892

Keyword

nonn,base

Author

Antti Karttunen, Nov 30 2017

Status

approved