OFFSET
1,27
COMMENTS
Multiplicative because A327936 is.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
FORMULA
Multiplicative with a(p^e) = (1 - p)^(e/p) if p | e, -(1 - p)^((e - 1)/p) if e == 1 (mod p), and 0 otherwise. - Amiram Eldar, Jan 26 2023
MATHEMATICA
f[p_, e_] := Switch[Mod[e, p], 0, (1 - p)^(e/p), 1, -(1 - p)^((e - 1)/p), _, 0]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Table[a[n], {n, 1, 100}] (* Amiram Eldar, Jan 26 2023 *)
PROG
CROSSREFS
KEYWORD
sign,mult
AUTHOR
Antti Karttunen, Jan 02 2023
STATUS
approved