A353671 a(n) = 1 if n is even and the odd part of n is a prime, otherwise 0.

0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 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, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 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, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 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) * A353670(n).

a(n) = A353670(n) - (A000035(n)*A010051(n)).

Prog

(PARI) A353671(n) = (!(n%2)&&isprime(n>>valuation(n, 2)));

Crossrefs

Characteristic function of A100368, numbers of the form 2^k * p where k > 0 and p is an odd prime.

Cf. A010051, A059841, A353670.

Sequence in context: A354353 A353669 A363915 * A353672 A323170 A215480

Adjacent sequences: A353668 A353669 A353670 * A353672 A353673 A353674

Keyword

nonn

Author

Antti Karttunen, May 04 2022

Status

approved