A358678 a(n) = 1 if n is odd and sigma(n) == 2 mod 4, otherwise 0.

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

Offset

1

Links

Antti Karttunen, Table of n, a(n) for n = 1..100000

Index entries for characteristic functions

Formula

a(n) = A000035(n) * A353812(n).

a(n) <= A359150(n).

Prog

(PARI) A358678(n) = ((n%2)&&(2==(sigma(n)%4)));

Crossrefs

Characteristic function of A191218.

Cf. A000035, A000203, A353812.

Differs from A359150 for the first time at n=105, where a(105) = 0, while A359150(105) = 1.

Sequence in context: A330551 A346618 A079260 * A359150 A354031 A354035

Adjacent sequences: A358675 A358676 A358677 * A358679 A358680 A358681

Keyword

nonn

Author

Antti Karttunen, Dec 17 2022

Status

approved