OFFSET
1,4
EXAMPLE
For n=4, (1*4)^(1/2) = 2 and (1*2*4)^(1/3) = 2. No other subset of {1,2,3,4} has integer geometric mean, so a(4)=2.
CROSSREFS
KEYWORD
nonn
AUTHOR
John W. Layman, Nov 11 2008
STATUS
approved