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A047180
Number of nonempty subsets of {1,2,...,n} in which exactly 1/6 of the elements are <= (n-1)/2.
0
0, 0, 0, 0, 0, 0, 0, 3, 4, 24, 30, 105, 126, 336, 392, 882, 1008, 2044, 2304, 4554, 5115, 10890, 12342, 29887, 34320, 90090, 104104, 273559, 315679, 795704, 913640, 2196740, 2508928, 5845008
OFFSET
1,8
CROSSREFS
Sequence in context: A276815 A223526 A032831 * A051394 A050801 A103093
KEYWORD
nonn
STATUS
approved