OFFSET
1
COMMENTS
Multiplicative because A355448 is.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..100000
FORMULA
a(1) = 1, and for n > 1, a(n) = -Sum_{d|n, d<n} A355448(n/d) * a(d).
Multiplicative with a(p) = 0, and for e > 1, a(p^e) = -1 if e == 2 or 3 (mod 4) and 1 otherwise. - Amiram Eldar, Feb 09 2023
MATHEMATICA
f[p_, e_] := If[Mod[e, 4] < 2, 1, -1]; f[p_, 1] = 0; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Feb 09 2023 *)
PROG
CROSSREFS
KEYWORD
sign,mult
AUTHOR
Antti Karttunen, Jul 14 2022
STATUS
approved