A380455 a(n) = 1 if A339792(n) is -1, otherwise 0, where A339792(n) is the third coefficient of the lindep transform of sigma.

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

Offset

1

Links

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

Index entries for characteristic functions.

Index entries for sequences related to sigma(n).

Formula

a(n) = [A339792(n) = -1], where A339792 is the Iverson bracket.

a(n) >= A010051(n).

Prog

(PARI)
A339792(n) = { my(v=lindep([sigma(n), n, 1])); (v*sign(v[1]))[3]; };
A380455(n) = (-1==A339792(n));

Crossrefs

Characteristic function of A380456.

Cf. A000203, A010051, A339792.

Sequence in context: A374130 A374466 A283991 * A353499 A359372 A327861

Adjacent sequences: A380452 A380453 A380454 * A380456 A380457 A380458

Keyword

nonn

Author

Antti Karttunen, Jan 25 2025

Status

approved