OFFSET
1,9
COMMENTS
Multiplicative because A071773 is.
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
FORMULA
Multiplicative with a(p^e) = (-1)^e * (1-p)^floor(e/2). - Sebastian Karlsson, Jan 03 2023
MATHEMATICA
f[p_, e_] := (-1)^e * (1-p)^Floor[e/2]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Jan 04 2023 *)
PROG
CROSSREFS
KEYWORD
sign,mult
AUTHOR
Antti Karttunen, Jan 02 2023
STATUS
approved