A147753 Number of maximum-size subsets of {1,2,3,...,n} whose geometric means are an integer.

0, 0, 0, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2

Offset

1,8

Links

Table of n, a(n) for n=1..20.

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

Crossrefs

A147751, A147752

Sequence in context: A249771 A030615 A336766 * A333355 A354523 A116531

Adjacent sequences: A147750 A147751 A147752 * A147754 A147755 A147756

Keyword

nonn

Author

John W. Layman, Nov 11 2008

Status

approved