A047200 Number of nonempty subsets of {1,2,...,n} in which exactly 3/5 of the elements are <= n/3.

0, 0, 0, 0, 0, 0, 0, 0, 15, 21, 28, 112, 144, 180, 450, 550, 660, 1815, 2275, 2821, 10192, 13230, 16940, 57680, 74256, 94248, 288456, 367080, 461700, 1427850, 1824690, 2310000, 7521360, 9684840, 12357532, 40225735, 51798175, 66098175

Offset

1,9

Links

Table of n, a(n) for n=1..38.

Crossrefs

Shares a bisection with A048045.

Sequence in context: A168104 A026048 A195527 * A070537 A324110 A285800

Adjacent sequences: A047197 A047198 A047199 * A047201 A047202 A047203

Keyword

nonn

Author

Clark Kimberling

Status

approved