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Number of maximum-size subsets of {1,2,3,...,n} whose geometric means are an integer.
2

%I #2 Mar 30 2012 17:37:58

%S 0,0,0,1,1,1,1,2,1,1,1,1,1,1,1,2,2,2,2,2

%N Number of maximum-size subsets of {1,2,3,...,n} whose geometric means are an integer.

%e 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 and only one has maximum size 3, so a(4)=1.

%Y A147751, A147752

%K nonn

%O 1,8

%A _John W. Layman_, Nov 11 2008