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A047198 Number of nonempty subsets of {1,2,...,n} in which exactly 1/5 of the elements are <= n/3. 0
0, 0, 0, 0, 1, 2, 10, 30, 45, 105, 213, 286, 558, 1110, 1500, 3300, 7435, 10415, 23855, 52871, 73255, 160615, 346745, 476910, 1047438, 2299998, 3181482, 7110522, 15770601, 21851202, 48767082, 107787262, 149093417, 331877557 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

Table of n, a(n) for n=1..34.

CROSSREFS

Sequence in context: A098408 A063564 A076440 * A290461 A162524 A065137

Adjacent sequences:  A047195 A047196 A047197 * A047199 A047200 A047201

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified October 16 00:50 EDT 2018. Contains 316252 sequences. (Running on oeis4.)