A127254 (0,1) sequence whose zero positions are indexed by twice the odious numbers given by A091855.

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

Offset: 0

Author

Paul Barry, Jan 10 2007

Keywords

• nonn
• base

Comments

0's appear at positions indexed by 2*A091855(n).

Links

• Antti Karttunen, Table of n, a(n) for n = 0..65537
• Index entries for characteristic functions.

Crossrefs

Row sums of A127253.

Cf. A000069, A091855.

Programs

Mathematica

a[n_] := If[EvenQ[n] && EvenQ[IntegerExponent[n/2, 2]] && OddQ[DigitCount[n/2, 2, 1]], 0, 1]; Array[a, 100, 0] (* Amiram Eldar, Aug 06 2023 *)

PARI

A127254(n) = if(n%2,1,!(hammingweight(n)%2 && !(valuation(n/2, 2)%2))); \\ After PARI-code in A091855. - Antti Karttunen, Nov 02 2018

Extensions

More terms from Antti Karttunen, Nov 02 2018