A353674 a(n) = 1 if n is an even number with an odd number of distinct prime factors, otherwise 0.

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

Offset

1

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for characteristic functions

Formula

a(n) = A059841(n) * A092248(n).

a(n) = A059841(n) - A353674(n).

a(n) = A092248(n) - A353673(n).

Mathematica

Table[If[EvenQ[n]&&OddQ[PrimeNu[n]], 1, 0], {n, 140}] (* Harvey P. Dale, Jul 16 2023 *)

Prog

(PARI) A353674(n) = (!(n%2) && (omega(n)%2));

Crossrefs

Cf. A001221, A059841, A092248, A353672, A353673, A353675.

Characteristic function of A098904.

Cf. also A353556.

Sequence in context: A288223 A353811 A116865 * A288512 A157687 A189668

Adjacent sequences: A353671 A353672 A353673 * A353675 A353676 A353677

Keyword

nonn

Author

Antti Karttunen, May 03 2022

Status

approved