A339664 Number of nonempty subsets of divisors of n whose geometric mean is an integer.

1, 2, 2, 5, 2, 4, 2, 8, 5, 4, 2, 10, 2, 4, 4, 15, 2, 10, 2, 10, 4, 4, 2, 16, 5, 4, 8, 10, 2, 8, 2, 26, 4, 4, 4, 63, 2, 4, 4, 16, 2, 8, 2, 10, 10, 4, 2, 30, 5, 10, 4, 10, 2, 16, 4, 16, 4, 4, 2, 20, 2, 4, 10, 45, 4, 8, 2, 10, 4, 8, 2, 196, 2, 4, 10, 10, 4, 8, 2, 30

Offset: 1

Author

Ilya Gutkovskiy, Dec 11 2020

Keywords

• nonn

Examples

			a(12) = 10 subsets: {1}, {2}, {3}, {4}, {6}, {12}, {1, 4}, {3, 12}, {1, 2, 4} and {3, 6, 12}.
		

Links

• Eric Weisstein's World of Mathematics, Geometric Mean
• Index entries for sequences related to divisors of numbers

Crossrefs

Cf. A027750, A100587, A326027, A339663, A339665, A339666.