OFFSET
1,4
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..10800
Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537
FORMULA
MATHEMATICA
f[p_, e_] := (p^(e + 1) - 1)/(p - 1) - 1; a[1] = 0; a[n_] := Times @@ f @@@ FactorInteger[n] - n; Array[a, 100] (* Amiram Eldar, May 06 2023 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jul 27 2020
STATUS
approved