OFFSET
1,4
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
FORMULA
MATHEMATICA
f[n_] := FromDigits[IntegerDigits[n, 3] /. 1 -> 0, 3]; Table[f@ n - DivisorSum[n, MoebiusMu[n/#] f@ # &], {n, 105}] (* Michael De Vlieger, Mar 17 2018 *)
PROG
CROSSREFS
KEYWORD
sign,base
AUTHOR
Antti Karttunen, Mar 14 2018
STATUS
approved