A353672 a(n) = 1 if n is an even number with an even number of distinct prime factors, otherwise 0.

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

Offset

1

Links

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

Index entries for characteristic functions

Formula

a(n) = [n is even] * [A001221(n) is even], where [ ] is the Iverson bracket.

a(n) = A059841(n) * (1-A092248(n)).

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

Prog

(PARI) A353672(n) = (!(n%2) && !(omega(n)%2));

Crossrefs

Characteristic function of A098902.

Cf. A001221, A059841, A092248, A353673, A353674, A353675.

Cf. also A353555.

Sequence in context: A353669 A363915 A353671 * A323170 A379118 A215480

Adjacent sequences: A353669 A353670 A353671 * A353673 A353674 A353675

Keyword

nonn

Author

Antti Karttunen, May 03 2022

Status

approved