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A047200 Number of nonempty subsets of {1,2,...,n} in which exactly 3/5 of the elements are <= n/3. 1
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 (list; graph; refs; listen; history; text; internal format)
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 A285800 A184041

Adjacent sequences:  A047197 A047198 A047199 * A047201 A047202 A047203

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified December 18 06:13 EST 2018. Contains 318215 sequences. (Running on oeis4.)