OFFSET
1,5
COMMENTS
If a(n)=0, then n is a balanced number (A020492).
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..2000
FORMULA
a(p^2) = 2*p+1, for prime p>=5. - Michel Marcus, Apr 07 2020
PROG
(PARI) { for (n=1, 2000, write("b063514.txt", n, " ", sigma(n)%eulerphi(n)) ) } \\ Harry J. Smith, Aug 24 2009
(Magma) [SumOfDivisors(n) mod EulerPhi(n): n in [1..85]]; // Bruno Berselli, Jan 31 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jul 31 2001
STATUS
approved