OFFSET
1,2
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..20000
FORMULA
MATHEMATICA
Table[n - DivisorSum[n, # &, ! CoprimeQ[#, n/#] &], {n, 84}] (* Michael De Vlieger, May 27 2019 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Antti Karttunen, May 23 2019
STATUS
approved