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A048087 Number of nonempty subsets of {1,2,...,n} in which exactly 1/5 of the elements are <= (n+3)/3. 0
0, 0, 0, 0, 0, 0, 3, 15, 20, 60, 140, 175, 360, 720, 891, 1935, 4455, 5775, 13895, 32487, 42484, 97188, 216580, 282165, 632706, 1418514, 1863880, 4259520, 9690000, 12833436, 29366007, 66481107, 88256147, 200571107, 452679491 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

LINKS

Table of n, a(n) for n=1..35.

CROSSREFS

Sequence in context: A083545 A224872 A097571 * A316751 A001897 A074214

Adjacent sequences:  A048084 A048085 A048086 * A048088 A048089 A048090

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified May 27 05:48 EDT 2020. Contains 334649 sequences. (Running on oeis4.)