A353556 a(n) = 1 if n is an even number with an odd number of prime factors (counted with multiplicity), otherwise 0.

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

Offset

1

Links

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

Index entries for characteristic functions

Formula

a(n) = A059841(n) * A066829(n).

a(n) = A059841(n) - A353555(n).

a(n) = A066829(n) - A353558(n).

Mathematica

Table[If[EvenQ[n]&&OddQ[PrimeOmega[n]], 1, 0], {n, 150}] (* Harvey P. Dale, Jan 12 2024 *)

Prog

(PARI) A353556(n) = ((!(n%2))&&(bigomega(n)%2));

Crossrefs

Characteristic function of A046470.

Cf. A059841, A066829, A353555, A353557, A353558.

Sequence in context: A330306 A300477 A355202 * A228495 A356982 A284683

Adjacent sequences: A353553 A353554 A353555 * A353557 A353558 A353559

Keyword

nonn

Author

Antti Karttunen, May 01 2022

Status

approved