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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, 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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified August 29 18:55 EDT 2024. Contains 375518 sequences. (Running on oeis4.)