OFFSET
0,3
LINKS
David Wasserman, Table of n, a(n) for n = 0..119
Wikipedia, Geometric mean
EXAMPLE
The a(1) = 1 through a(12) = 16 subsets:
{1} {1} {1} {1} {1} {1} {1} {1} {1} {1} {1} {1}
{2} {2} {2} {2} {2} {2} {2} {2} {2} {2} {2}
{3} {3} {3} {3} {3} {3} {3} {3} {3} {3}
{4} {4} {4} {4} {4} {4} {4} {4} {4}
{5} {5} {5} {5} {5} {5} {5} {5}
{6} {6} {6} {6} {6} {6} {6}
{7} {7} {7} {7} {7} {7}
{8} {8} {8} {8} {8}
{2,8} {9} {9} {9} {9}
{1,9} {10} {10} {10}
{2,8} {1,9} {11} {11}
{2,8} {1,9} {12}
{2,8} {1,9}
{2,8}
{3,6,12}
{3,4,9,12}
MATHEMATICA
Table[Length[Select[Subsets[Range[n]], IntegerQ[Mean[#]]&&IntegerQ[GeometricMean[#]]&]], {n, 0, 10}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Jul 16 2019
EXTENSIONS
More terms from David Wasserman, Aug 03 2019
STATUS
approved