OFFSET
1,7
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..20000
MATHEMATICA
f[p_, e_] := (1 - p); d[1] = 1; d[n_] := Times @@ f @@@ FactorInteger[n]; k[n_] := (n / 2^IntegerExponent[n, 2] + 1)/2; a[n_] := DivisorSum[n, k[#] * d[n/#] &]; Array[a, 100] (* Amiram Eldar, Nov 16 2021 *)
PROG
CROSSREFS
KEYWORD
sign
AUTHOR
Antti Karttunen, Nov 15 2021
STATUS
approved