OFFSET
1,6
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..1000
PROG
(PARI) a(n)={sumdiv(n, d, if(gcd(d, n/d)==1, d)) - eulerphi(n) - numdiv(n)}
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Jason Earls, Aug 06 2001
STATUS
approved