A323158 If n is a square, a(n) = 1-(n mod 2), otherwise a(n) = (n mod 2); a(n) = A049820(n) mod 2, where A049820(n) = n - number of divisors of n.

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

Offset

1

Comments

For all i, j: A305801(i) = A305801(j) => a(i) = a(j).

Links

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

Index entries for characteristic functions

Formula

a(n) = A000035(A049820(n)) = A000035(n+A010052(n)).

Mathematica

A323158[n_] := Mod[n - DivisorSigma[0, n], 2]; Array[A323158, 100] (* Paolo Xausa, Jan 15 2025 *)

Prog

(PARI) A323158(n) = ((n-numdiv(n))%2);

Crossrefs

Cf. A000005, A000035, A010052, A049820, A262514, A305801, A322996.

Sequence in context: A073089 A373470 A373141 * A011657 A354896 A359606

Adjacent sequences: A323155 A323156 A323157 * A323159 A323160 A323161

Keyword

nonn

Author

Antti Karttunen, Jan 09 2019

Status

approved