A361022 a(n) = 1 if d(n) divides d(n+1), otherwise 0, where d(n) is number of positive divisors of n.

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

Offset

1

Links

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

Index entries for characteristic functions

Mathematica

a[n_] := If[Divisible @@ DivisorSigma[0, n + {1, 0}], 1, 0]; Array[a, 100] (* Amiram Eldar, Mar 02 2023 *)

Prog

(PARI) A361022(n) = !(numdiv(1+n)%numdiv(n));

Crossrefs

Characteristic function of A057922.

Cf. A000005.

Sequence in context: A267520 A114915 A360120 * A341754 A074711 A004585

Adjacent sequences: A361019 A361020 A361021 * A361023 A361024 A361025

Keyword

nonn

Author

Antti Karttunen, Mar 02 2023

Status

approved