OFFSET
1,1
LINKS
T. Goto and S. Shibata, All numbers whose positive divisors have integral harmonic mean up to 300, Math. Comput. 73 (2004), 475-491.
EXAMPLE
k = 61 is a term because m*tau(m)/sigma(m) = 61 if and only if m = 2^30 * 61 * (2^31-1) or m = 2^60 * (2^61-1). - Jinyuan Wang, Mar 05 2020
CROSSREFS
KEYWORD
nonn,more
AUTHOR
R. K. Guy, Feb 08 2004
STATUS
approved