A347523 - OEIS

A347523

Characteristic function of nonpowers of 2.

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

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OFFSET

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..65537

Index entries for characteristic functions

FORMULA

a(n) = 1 - A209229(n).

a(A000079(n)) = 0; a(A057716(n)) = 1.

MATHEMATICA

a[n_] := Boole[2^IntegerExponent[n, 2] != n]; Array[a, 100, 0] (* Amiram Eldar, Sep 05 2021 *)

PROG

(PARI) A347523(n) = if(!n, 1, 0!=bitand(n, n-1)); \\ Antti Karttunen, Dec 13 2021